Kolloquien - Max Planck Institut für Quantenoptik
http://www.mpq.mpg.de/5381003/colloquien-ve.rss
Verstaltungen des Max Planck Institut für Quantenoptik.deThu, 17 Aug 2017 00:00:00 +0200Wed, 12 Jul 2017 12:03:50 +0200Fundamental Physics with (weird) Magnetic Resonance (Prof. D. Budker)
http://www.mpq.mpg.de/events/9487/5381003
<strong>Vortragender</strong>: Prof. Dmitry Budker<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 25.07.2017 14:30 - 15:30<br><strong>Zusammenfassung</strong>: I will discuss the ongoing experiments (CASPEr and GNOME) searching for ultralight galactic dark matter using magnetic-resonance techniques and a new approach to measuring parity violation in chiral molecular systems. Wed, 12 Jul 2017 12:03:50 +0200http://www.mpq.mpg.de/events/9487/5381003?14998538302017-07-12T12:03:50+02:00Collective quantum dynamics: from information scrambling to emergent hydrodynamics (Prof. M. Knap)
http://www.mpq.mpg.de/events/9290/5381003
<strong>Speaker</strong>: Prof. Dr. Michael Knap<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.07.2017 14:30 - 15:30<br><strong>Summary</strong>: Generic, clean quantum many-body systems approach a thermal equilibrium after a long time evolution. In order to reach a global equilibrium, conserved quantities have to be transported across the whole system which is a rather slow process governed by diffusion.Wed, 05 Jul 2017 09:02:43 +0200http://www.mpq.mpg.de/events/9290/5381003?14992381632017-07-05T09:02:43+02:00Quantum Measurements on Trapped Ions (Prof. J. Home)
http://www.mpq.mpg.de/events/9289/5381003
<strong>Speaker</strong>: Prof. Dr. Jonathan Home<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.07.2017 14:30 - 15:30<br><strong>Summary</strong>: Measurement as defined in quantum physics rarely corresponds to what is performed in the laboratory. Wed, 28 Jun 2017 09:32:15 +0200http://www.mpq.mpg.de/events/9289/5381003?14986351352017-06-28T09:32:15+02:00Optical Atomic Clocks: From Laboratory Experiments to International Time Keeping (Dr. H. Margolis)
http://www.mpq.mpg.de/events/10328/5381003
<strong>Vortragender</strong>: Dr. Helen Margolis<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 20.07.2017 13:30 - 14:30<br><strong>Zusammenfassung</strong>: Optical atomic clocks based on laser-cooled atoms or single trapped ions have made rapid progress over the past few years, with the most advanced now having reached levels of stability and uncertainty that significantly surpass the performance of caesium primary frequency standards.Mon, 19 Jun 2017 14:36:16 +0200http://www.mpq.mpg.de/events/10328/5381003?14978757762017-06-19T14:36:16+02:00First principles modeling of Light-Matter interactions within QED-TDDFT: From Weak to Strong Coupling in QED-Chemistry and Materials (Prof. A. Rubio)
http://www.mpq.mpg.de/events/9395/5381003
<strong>Vortragender</strong>: Prof. Dr. Angel Rubio<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 06.06.2017 14:30 - 15:30<br><strong>Zusammenfassung</strong>: Computer simulations that predict the light-induced change in the physical and chemical properties of complex systems, molecules, nanostructures and solids usually ignore the quantum nature of light.Mon, 08 May 2017 10:05:59 +0200http://www.mpq.mpg.de/events/9395/5381003?14942307592017-05-08T10:05:59+02:00Strong coupling of two light fields mediated by a single atom (C. Hamsen) / Energy as a Detector of Nonlocality of Many-Body Spin Systems (Dr. J. Tura)
http://www.mpq.mpg.de/events/9514/5381003
<strong>Vortragender</strong>: Christoph Hamsen, Doktorand, Quantendynamik / Dr. Jordi Tura, PostDoc, Theorie<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 16.05.2017 14:30 - 15:30Fri, 05 May 2017 10:29:27 +0200http://www.mpq.mpg.de/events/9514/5381003?14939729672017-05-05T10:29:27+02:00Genome editing and the CRISPR/cas revolution (Prof. K. Förstemann)
http://www.mpq.mpg.de/events/9228/5381003
<strong>Vortragender</strong>: Prof. Dr. Klaus Förstemann<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 23.05.2017 14:30 - 15:30<br><strong>Zusammenfassung</strong>: I will present the origins of the prokaryotic (i.e. bacteria and archaea) CRISPR/cas systems, then describe how one particular variant (Streptococcus pyogenes cas9) has been adapted and optimized for use in eukaryotic cells.Thu, 04 May 2017 10:14:16 +0200http://www.mpq.mpg.de/events/9228/5381003?14938856562017-05-04T10:14:16+02:00Potential Energy Surfaces and Berry Phases beyond the Born-Oppenheimer Approximation (Prof. E. Gross)
http://www.mpq.mpg.de/events/9227/5381003
<strong>Vortragender</strong>: Prof. Dr. Eberhard K. U. Gross<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 02.05.2017 14:30 - 15:30<br><strong>Zusammenfassung</strong>: The starting point of essentially all modern electronic-structure techniques is the Born-Oppenheimer approximation. It not only makes calculations feasible, it also provides us with an intuitive picture of chemical reactions.Tue, 18 Apr 2017 09:50:52 +0200http://www.mpq.mpg.de/events/9227/5381003?14925018522017-04-18T09:50:52+02:00Manipulating nuclei with laser light: the quest of Thorium-229 (Prof. T. Schumm)
http://www.mpq.mpg.de/events/9509/5381003
<strong>Vortragender</strong>: Prof. Dr. Thorsten Schumm<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 27.06.2017 14:30 - 15:30<br><strong>Zusammenfassung</strong>: The radio isotope Thorium-229 is expected to present a remarkably low-energy excited (isomer) state of the nucleus which is expected around 7.8(5) eV.Tue, 11 Apr 2017 10:06:26 +0200http://www.mpq.mpg.de/events/9509/5381003?14918979862017-04-11T10:06:26+02:00Spin resolved microscopy of doped Hubbard chains (T. Hilker) / Testing Bell's inequality with atoms entangled over a large distance (Dr. W. Rosenfeld)
http://www.mpq.mpg.de/events/9515/5381003
<strong>Vortragender</strong>: Timon Hilker, Doktorand, QMBS / Dr. Wenjamin Rosenfeld, PostDoc, Laser Spectroscopy<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 09.05.2017 14:30 - 15:30Wed, 05 Apr 2017 12:15:23 +0200http://www.mpq.mpg.de/events/9515/5381003?14913873232017-04-05T12:15:23+02:00Quantum optics with trapped ions – from single ion heat engines to ions in vortex laser fields (Prof. F. Schmidt-Kaler)
http://www.mpq.mpg.de/events/9288/5381003
<strong>Speaker</strong>: Prof. Dr. Ferdinand Schmidt-Kaler<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.06.2017 14:30 - 15:30<br><strong>Summary</strong>: Trapped single ions and ion crystal exhibit excellent control of the internal spin– and the external motional-degree of freedom. Multi-particle quantum entangled states are generated with high fidelity in view of a future quantum computer with trapped ions.Tue, 28 Mar 2017 12:02:32 +0200http://www.mpq.mpg.de/events/9288/5381003?14906953522017-03-28T12:02:32+02:00Are we quantum computers, or merely clever robots? (Prof. M. Fisher)
http://www.mpq.mpg.de/events/9291/5381003
<strong>Speaker</strong>: Prof. Dr. Matthew Fisher<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.07.2017 14:30 - 15:30<br><strong>Summary</strong>: Of course quantum information processing is not possible in the warm wet brain. There is, however, one \loophole" - oered by nuclear spins - that must be closed before acknowledging that we are merely clever robots.Tue, 14 Mar 2017 14:24:47 +0100http://www.mpq.mpg.de/events/9291/5381003?14894978872017-03-14T14:24:47+01:00 The Alchemy of Vacuum - Hybridizing Light and Matter (Prof. T. Ebbesen)
http://www.mpq.mpg.de/events/9229/5381003
<strong>Speaker</strong>: Prof. Dr. Thomas W. Ebbesen<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.06.2017 14:30 - 15:30<br><strong>Summary</strong>: Strong coupling of light and matter can give rise to a multitude of exciting physical effects through the formation of hybrid light-matter states.Tue, 07 Mar 2017 13:53:38 +0100http://www.mpq.mpg.de/events/9229/5381003?14888912182017-03-07T13:53:38+01:00Schrödinger Cat States and Quantum Error Correction for Bosonic Modes (Prof. S. Girvin)
http://www.mpq.mpg.de/events/8801/5381003
<strong>Speaker</strong>: Prof. Dr. Steven Girvin, Department of Physics, Yale University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.02.2017 14:30 - 15:30<br><strong>Summary</strong>: Recent remarkable experimental progress in ‘circuit QED’ now allows realization of extremely strong dispersive coupling between superconducting qubits and microwave photons in resonators.Tue, 31 Jan 2017 10:13:01 +0100http://www.mpq.mpg.de/events/8801/5381003?14858539812017-01-31T10:13:01+01:00Field-Resolved Infrared Spectroscopy (Dr. I. Pupeza) / A cavity-mediated photon-photon quantum gate (S. Welte)
http://www.mpq.mpg.de/events/7299/5381003
<strong>Speaker</strong>: Dr. Ioachim Pupeza, Scientist, Attosecond Physics Division / Stephan Welte, Doctoral Candidate, Quantum Dynamics Division <br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.01.2017 14:30 - 15:30Wed, 11 Jan 2017 12:40:45 +0100http://www.mpq.mpg.de/events/7299/5381003?14841348452017-01-11T12:40:45+01:00Triggering Molecular Processes with Light (Prof. J. Wachtveitl)
http://www.mpq.mpg.de/events/7302/5381003
<strong>Speaker</strong>: Prof. Dr. Josef Wachtveitl, Institute of Physical and Theoretical Chemistry, Frankfurt/M.<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 31.01.2017 14:30 - 15:30<br><strong>Summary</strong>: Molecular systems that can be remotely controlled by light are gaining increasing importance in bio-sciences. High spatial and temporal precision is achievable with short laser pulses and in principle there are three approaches for light regulation.Tue, 20 Dec 2016 11:23:24 +0100http://www.mpq.mpg.de/events/7302/5381003?14822294042016-12-20T11:23:24+01:00Chiral Quantum Optics (Prof. A. Rauschenbeutel)
http://www.mpq.mpg.de/events/7300/5381003
<strong>Speaker</strong>: Prof. Dr. Arno Rauschenbeutel, Vienna Center for Quantum Science and Technology (VCQ), TU Wien, Austria<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.01.2017 14:30 - 15:30<br><strong>Summary</strong>: Controlling the interaction of light and matter is the basis for diverse applications ranging from light technology to quantum information processing. Nowadays, many of these applications are based on nanophotonic structures.Thu, 15 Dec 2016 11:52:29 +0100http://www.mpq.mpg.de/events/7300/5381003?14817991492016-12-15T11:52:29+01:00Quantum Nano-Optics with Organic Molecules and Rare Earth Ions (Prof. V. Sadoghdar)
http://www.mpq.mpg.de/events/7297/5381003
<strong>Speaker</strong>: Prof. Dr. Vahid Sandoghdar, MPI für die Physik des Lichts, Erlangen<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 06.12.2016 14:30 - 15:30<br><strong>Summary</strong>: I plan to start this presentation with an overview of our work over the past decade on the efficient coupling of light and single quantum emitters, leading to the single-photon communication of two individual molecules at long distances [1].Wed, 30 Nov 2016 11:17:09 +0100http://www.mpq.mpg.de/events/7297/5381003?14805010292016-11-30T11:17:09+01:00Searching for dark fields with atom interferometry (Prof. P. Hamilton)
http://www.mpq.mpg.de/events/7307/5381003
<strong>Speaker</strong>: Prof. Dr. Paul Hamilton<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 09.12.2016 11:00 - 12:00<br><strong>Summary</strong>: One of the great mysteries of modern physics is the identity of nearly 95% of our Universe, which has been labelled as dark matter and dark energy. The high precision of atom interferometry gives a new way to explore this mystery.Wed, 23 Nov 2016 11:22:20 +0100http://www.mpq.mpg.de/events/7307/5381003?14798965402016-11-23T11:22:20+01:00Micro Cavity-based Spectroscopy of individual Nano Particles (M. Mader) / PEPS and local (gauge) symmetries (Dr. E. Zohar)
http://www.mpq.mpg.de/events/7296/5381003
<strong>Speaker</strong>: Mathias Mader, Doctoral Candidate, Laser Spectroscopy Division / Dr. Erez Zohar, Postdoc, Theory Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.11.2016 14:30 - 15:30Mon, 14 Nov 2016 11:52:16 +0100http://www.mpq.mpg.de/events/7296/5381003?14791207362016-11-14T11:52:16+01:00Thermodynamics and order beyond equilibrium - the physics of periodically driven quantum systems (Prof. R. Moessner)
http://www.mpq.mpg.de/events/7294/5381003
<strong>Speaker</strong>: Prof. Dr. Roderich Moessner, Direktor am MPI für Physik Komplexer Systeme, Dresden<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.11.2016 14:30 - 15:30<br><strong>Summary</strong>: The field of thermodynamics is one of the crown jewels of classical physics. However, only comparatively recently, due to the advent of experiments in cold atomic systems with long coherence times, has our detailed understanding of its connection to quantum statistical mechanics seen remarkable progress.Mon, 24 Oct 2016 12:30:18 +0200http://www.mpq.mpg.de/events/7294/5381003?14773050182016-10-24T12:30:18+02:00Controlling charge and spin faster than a cycle of light (Prof. R. Huber)
http://www.mpq.mpg.de/events/7172/5381003
<strong>Speaker</strong>: Professor Rupert Huber, Universität Regensburg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.07.2014 12:30<br><strong>Summary</strong>: The physical properties of condensed matter are often caused by ultrafast phenomena involving low-energy elementary excitations, such as lattice vibrations, spin precession, plasmons, or superconducting energy gaps. Tue, 18 Oct 2016 13:04:57 +0200http://www.mpq.mpg.de/events/7172/5381003?14767886972016-10-18T13:04:57+02:00Intense Femtosecond Electron Pulses for Single-Shot Ultrafast Electron Diffraction and Electron Deflectometry (Prof. S. Sakabe)
http://www.mpq.mpg.de/events/7174/5381003
<strong>Speaker</strong>: Professor Dr. Shuji Sakabe, University of Kyoto, Japan<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.10.2014 14:30 - 16:00<br><strong>Summary</strong>: Time-resolved electron diffraction and electron deflectometry using femtosecond electron pulses are useful techniques for observing ultrafast changes in the atomic-scale structure of matter and in the electromagnetic fields near matter during physical phenomena. Tue, 18 Oct 2016 13:01:41 +0200http://www.mpq.mpg.de/events/7174/5381003?14767885012016-10-18T13:01:41+02:00Many body localization and the breakdown of ergodicity in quantum systems (Prof. E. Altman)
http://www.mpq.mpg.de/events/7173/5381003
<strong>Speaker</strong>: Professor Dr. Ehud Altman, Weizmann Institute of Science, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.10.2014 14:30 - 16:00<br><strong>Summary</strong>: Many body localization and the breakdown of ergodicity in quantum systemsTue, 18 Oct 2016 12:57:32 +0200http://www.mpq.mpg.de/events/7173/5381003?14767882522016-10-18T12:57:32+02:00Generating multi-atom entanglement by quantum Zeno dynamics in an optical fiber micro cavity (Prof. J. Reichel)
http://www.mpq.mpg.de/events/7175/5381003
<strong>Speaker</strong>: Professor Dr. Jakob Reichel, Laboratoire Kastler Brossel de l’E.N.S., France<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.10.2014 14:30 - 16:00<br><strong>Summary</strong>: Multiparticle entangled quantum states, required as a resource in quantum-enhanced metrology and quantum computing, are usually generated by unitary operations exclusively, while carefully shielding the system from any coupling to the environment. Tue, 18 Oct 2016 12:54:16 +0200http://www.mpq.mpg.de/events/7175/5381003?14767880562016-10-18T12:54:16+02:00Creating topological matter by shaking atomic gases (Prof. N. Goldman)
http://www.mpq.mpg.de/events/7176/5381003
<strong>Speaker</strong>: Professor Dr. Nathan Goldman, Collège de France (Paris, France) and Université Libre de Bruxelles (Belgium)<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.11.2014 14:30 - 16:00<br><strong>Summary</strong>: Quantum systems can reach unusual states of matter when they are driven by fast time-periodic modulations. Tue, 18 Oct 2016 12:50:42 +0200http://www.mpq.mpg.de/events/7176/5381003?14767878422016-10-18T12:50:42+02:00Condensed matter physics for quantum information (Prof. Ch. Marcus)
http://www.mpq.mpg.de/events/7179/5381003
<strong>Speaker</strong>: Professor Dr. Charles Marcus, University of Copenhagen, Denmark<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.11.2014 14:30 - 16:00<br><strong>Summary</strong>: This talk will describe some of the physics challenges that arise in the pursuit of quantum information technology.Tue, 18 Oct 2016 12:49:47 +0200http://www.mpq.mpg.de/events/7179/5381003?14767877872016-10-18T12:49:47+02:00Demonstration of Deterministic Photon-Photon Interactions by Interference-Based Single Photon Nonlinearity (Prof. B. Dayan)
http://www.mpq.mpg.de/events/7180/5381003
<strong>Speaker</strong>: Professor Dr. Barak Dayan, Weizmann Institute of Science, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.11.2014 14:30 - 16:00<br><strong>Summary</strong>: Achieving optical nonlinear interactions at the level of single photons has been the subject of extensive research in the last couple of decades. Tue, 18 Oct 2016 12:49:05 +0200http://www.mpq.mpg.de/events/7180/5381003?14767877452016-10-18T12:49:05+02:00The Higgs Boson at the LHC - From discovery to measurements (Prof. K. Jakobs)
http://www.mpq.mpg.de/events/7181/5381003
<strong>Speaker</strong>: Professor Karl Jakobs, Universität Freiburg, Germany<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 25.11.2014 14:30 - 16:00<br><strong>Summary</strong>: With the announcement of the discovery of a Higgs-like particle in July 2012 by the two general-purpose experiments ATLAS and CMS at the Large Hadron Collider (LHC) at CERN particle physics has entered a new era. Tue, 18 Oct 2016 12:41:44 +0200http://www.mpq.mpg.de/events/7181/5381003?14767873042016-10-18T12:41:44+02:00Quantum matter based on ultracold molecules (Prof. Jun Ye)
http://www.mpq.mpg.de/events/7182/5381003
<strong>Speaker</strong>: Professor Dr. Jun Ye, JILA, National Institute of Standards and Technology and University of Colorado, 440 UCB, Boulder CO 80309-0440 USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 02.12.2014 14:30 - 16:00<br><strong>Summary</strong>: Molecules cooled to ultralow temperatures provide fundamental new insights to strongly correlated quantum systems, molecular interactions and chemistry in the quantum regime, and precision measurement. Tue, 18 Oct 2016 12:29:58 +0200http://www.mpq.mpg.de/events/7182/5381003?14767865982016-10-18T12:29:58+02:00Quantum communication, repeaters, qubit amplifiers and large entanglement (Prof. N. Gisin)
http://www.mpq.mpg.de/events/7183/5381003
<strong>Speaker</strong>: Professor Dr. Nicolas Gisin, Universität Genf, Schweiz<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.12.2014 14:30 - 16:00<br><strong>Summary</strong>: Quantum communications is the art of transferring a quantum state from one location to a distant one. Tue, 18 Oct 2016 12:22:19 +0200http://www.mpq.mpg.de/events/7183/5381003?14767861392016-10-18T12:22:19+02:00An Aharonov-Bohm-type interferometer for determining Bloch band topology using ultracold atoms (L. Duca) / Rotational cooling of trapped polyatomic molecules (R. Glöckner)
http://www.mpq.mpg.de/events/7184/5381003
<strong>Speaker</strong>: M.Sc. Lucia Duca, MPQ, QMBS Division / M.Sc. Rosa Glöckner, MPQ, QD Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 16.12.2014 14:30 - 16:00Tue, 18 Oct 2016 12:20:21 +0200http://www.mpq.mpg.de/events/7184/5381003?14767860212016-10-18T12:20:21+02:00Certain aspects of entanglement in quantum many-body systems (Prof. B. Kraus)
http://www.mpq.mpg.de/events/7185/5381003
<strong>Speaker</strong>: Professor Dr. Barbara Kraus, Universität Innsbruck, Austria<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.01.2015 14:30 - 16:00<br><strong>Summary</strong>: Many applications of quantum information rely on the potentiality of quantum systems to be correlated. For pure states, these correlations coincide with entanglement.Tue, 18 Oct 2016 12:13:42 +0200http://www.mpq.mpg.de/events/7185/5381003?14767856222016-10-18T12:13:42+02:00Towards deterministic nanoscale light-matter quantum interfaces with defect centers in diamond (Dr. M. Weber) / Nanophotonics for quantum information and simulation (Dr. A. González Tudela)
http://www.mpq.mpg.de/events/7186/5381003
<strong>Speaker</strong>: Dr. Markus Weber, MPQ, Abt. Laserspektroskopie / Dr. A. González Tudela, MPQ, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.01.2015 14:30 - 16:00Tue, 18 Oct 2016 12:11:48 +0200http://www.mpq.mpg.de/events/7186/5381003?14767855082016-10-18T12:11:48+02:00Introduction to the AdS/CFT correspondence, its generalizations and applications (Prof. J. Erdmenger)
http://www.mpq.mpg.de/events/11/5381003
<strong>Vortragender</strong>: Prof. Johanna Erdmenger, MPI für Physik<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 12.02.2015 14:30 - 17:00<br><strong>Zusammenfassung</strong>: I will give an introduction to the AdS/CFT correspondence and its generalization for non-experts.Tue, 18 Oct 2016 11:56:09 +0200http://www.mpq.mpg.de/events/11/5381003?14767845692016-10-18T11:56:09+02:00Emergence of Chiral Order in SU(2) lattice gauge theory in 1D (Dr. P. Silvi)
http://www.mpq.mpg.de/events/10/5381003
<strong>Vortragender</strong>: Dr. Pietro Silvi, Universität Ulm<br><strong>Raum</strong>: Herbert Walther Lecture Hall<br><br><strong>Datum</strong>: 04.03.2015 11:30 - 13:00<br><strong>Zusammenfassung</strong>: We study the ground state properties of the simplest quantum link model undergoing a SU(2) lattice gauge invariance, in one spatial dimension. Tue, 18 Oct 2016 11:50:35 +0200http://www.mpq.mpg.de/events/10/5381003?14767842352016-10-18T11:50:35+02:00Cold Chemistry with Cold Molecules (Prof. E. Narevicius)
http://www.mpq.mpg.de/events/7211/5381003
<strong>Speaker</strong>: Professor Dr. Edvardas Narevicius, Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.04.2015 14:30 - 16:00<br><strong>Summary</strong>: There has been a long-standing quest to observe chemical reactions at low temperatures where reaction rates and pathways are governed by quantum mechanical effects or long range interactions. Tue, 18 Oct 2016 11:38:47 +0200http://www.mpq.mpg.de/events/7211/5381003?14767835272016-10-18T11:38:47+02:00Cosmological results from the Planck satellite (Prof. S. White)
http://www.mpq.mpg.de/events/7212/5381003
<strong>Speaker</strong>: Professor Dr. Simon D. M. White, MPI für Astrophysik, Garching<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.04.2015 14:30 - 16:00<br><strong>Summary</strong>: ESA's Planck mission is the third generation satellite to study the Cosmic Microwave Background.Tue, 18 Oct 2016 11:37:46 +0200http://www.mpq.mpg.de/events/7212/5381003?14767834662016-10-18T11:37:46+02:00UV-induced damage of DNA: the role of short- and longlived excited states (Prof. W. Zinth)
http://www.mpq.mpg.de/events/7213/5381003
<strong>Speaker</strong>: Professor Dr. Wolfgang Zinth, Lehrstuhl fuer BioMolekulare Optik, Fakultaet fuer Physik, Ludwig-Maximilians-Universität, München<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 05.05.2015 14:30 - 16:00<br><strong>Summary</strong>: UV-irradiation by sun-light imposes a permanent menace to live on earth. UV-radiation causes serious loss of genetic information. Tue, 18 Oct 2016 11:34:18 +0200http://www.mpq.mpg.de/events/7213/5381003?14767832582016-10-18T11:34:18+02:00Nano-optics gets quantum (Prof. R. Quidant)
http://www.mpq.mpg.de/events/7214/5381003
<strong>Speaker</strong>: Professor Dr. Romain Quidant, ICFO, Barcelona, Spain<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.05.2015 14:30 - 16:00<br><strong>Summary</strong>: Extensive research in Nano-optics over the last decade has made possible controlling optical fields on the nanometer scale. Such concentration of light, well below the limit of diffraction, opens plenty of new routes towards enhanced interaction with tiny amounts of matter down to the single molecule/atom level.Tue, 18 Oct 2016 11:33:21 +0200http://www.mpq.mpg.de/events/7214/5381003?14767832012016-10-18T11:33:21+02:00Antiferromagnetism with Ultracold Atoms (Prof. R. Hulet)
http://www.mpq.mpg.de/events/7215/5381003
<strong>Speaker</strong>: Professor Dr. Randall G. Hulet, Department of Physics and Astronomy, Rice University Houston, Texas, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.05.2015 15:00 - 17:00<br><strong>Summary</strong>: Ultracold atoms on optical lattices form a versatile platform for studying many-body physics, with the potential of addressing some of the most important issues in strongly correlated matter.Tue, 18 Oct 2016 11:32:02 +0200http://www.mpq.mpg.de/events/7215/5381003?14767831222016-10-18T11:32:02+02:00Snapshots of primary photoinduced events in biomolecules by tunable few-optical-cycle pulses (Prof. G. Cerullo)
http://www.mpq.mpg.de/events/7216/5381003
<strong>Speaker</strong>: Professor Dr. Giulio Cerullo, Politecnico di Milano, Italy<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.05.2015 14:30 - 16:00<br><strong>Summary</strong>: Many light-induced processes in biomolecules, such as energy relaxation, energy/charge transfer and conformational changes, occur on ultrafast timescales, ranging from 10-14 to 10-13 s. Tue, 18 Oct 2016 11:30:39 +0200http://www.mpq.mpg.de/events/7216/5381003?14767830392016-10-18T11:30:39+02:00Quantum thermalization, many-body Anderson localization and the entanglement frontier (Prof. D. Huse)
http://www.mpq.mpg.de/events/7217/5381003
<strong>Speaker</strong>: Professor Dr. David Huse, Department of Physics, Princeton University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 02.06.2015 14:30 - 16:00<br><strong>Summary</strong>: Progress in physics and quantum information science motivates much recent study of the behavior of extensively-entangled many-body quantum systems fully isolated from their environment, and thus undergoing unitary time evolution. Tue, 18 Oct 2016 11:26:48 +0200http://www.mpq.mpg.de/events/7217/5381003?14767828082016-10-18T11:26:48+02:00Quantum simulation using ultracold atoms in a non-standard optical lattice (Prof. Y. Takahashi)
http://www.mpq.mpg.de/events/7218/5381003
<strong>Speaker</strong>: Professor Dr. Yoshiro Takahashi, University of Kyoto, Japan<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 09.06.2015 14:30 - 16:00<br><strong>Summary</strong>: A system of ultracold atoms in an optical lattice is an ideal quantum simulator of a strongly correlated quantum many-body system and also a topological quantum system due to the high-controllability of system parameters.Tue, 18 Oct 2016 11:22:03 +0200http://www.mpq.mpg.de/events/7218/5381003?14767825232016-10-18T11:22:03+02:00The enigma of optical momentum (Prof. S. Barnett)
http://www.mpq.mpg.de/events/7219/5381003
<strong>Speaker</strong>: Professor Dr. Stephen Barnett, University of Glasgow, Scotland<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.06.2015 14:30 - 16:00<br><strong>Summary</strong>: It is more than 100 years since the battle began to determine the correct form of the momentum of light inside a material medium. Tue, 18 Oct 2016 11:11:07 +0200http://www.mpq.mpg.de/events/7219/5381003?14767818672016-10-18T11:11:07+02:00Quantum dynamics in spatially resolved two-atom cavity QED (A. Neuzner) / Solid State Attosecond Dynamics (Dr. M. Schultze)
http://www.mpq.mpg.de/events/7221/5381003
<strong>Speaker</strong>: Andreas Neuzner, Abteilung Quantendynamik / Dr. Martin Schultze, Abteilung Attosekundenphysik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 23.06.2015 14:30 - 16:00<br><strong>Summary</strong>: abstracts...Tue, 18 Oct 2016 11:04:10 +0200http://www.mpq.mpg.de/events/7221/5381003?14767814502016-10-18T11:04:10+02:00Many-Body Localisation of Fermions in a 1D Quasi-Random Disordered Lattice (M. Schreiber) / Photon Transmissions in Rydberg-EIT Systems by Multi-Photon Scattering Theory (Dr. T. Shi)
http://www.mpq.mpg.de/events/7222/5381003
<strong>Speaker</strong>: Dipl. Phys. Michael Schreiber, Abt. Quanten-Vielteilchensysteme / Dr. Tao Shi, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.07.2015 14:30 - 16:00<br><strong>Summary</strong>: abstracs...Tue, 18 Oct 2016 11:02:39 +0200http://www.mpq.mpg.de/events/7222/5381003?14767813592016-10-18T11:02:39+02:00Electro-optic sampling of near-infrared waves, and attosecond polarization spectroscopy (Dr. Karpowicz) / Laser spectroscopy of pionic and antiprotonic helium atoms (Dr. Hori)
http://www.mpq.mpg.de/events/7265/5381003
<strong>Speaker</strong>: Dr. N. Karpowicz, MPQ, Attosecond Physics Division / Dr. M. Hori, MPQ, Laser Spectroscopy Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 19.04.2016 14:30 - 16:00<br><strong>Summary</strong>: abstracts...Tue, 18 Oct 2016 11:00:38 +0200http://www.mpq.mpg.de/events/7265/5381003?14767812382016-10-18T11:00:38+02:00A Thouless Quantum Pump with Ultracold Bosonic Atoms in an Optical Superlattice (M. Lohse) / Direct cooling of polar molecules to submillikelvin temperatures (A. Prehn)
http://www.mpq.mpg.de/events/7273/5381003
<strong>Speaker</strong>: Michael Lohse, MPQ, QMBS Division / Alexander Prehn, MPQ, QD Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.06.2016 14:30 - 15:30<br><strong>Summary</strong>: abstracts...Tue, 18 Oct 2016 10:58:30 +0200http://www.mpq.mpg.de/events/7273/5381003?14767811102016-10-18T10:58:30+02:00A microscope for Fermi gases (A. Omran) / Methods to observe topological properties in a fermionic ladder model (Dr. M. Burrello)
http://www.mpq.mpg.de/events/7241/5381003
<strong>Speaker</strong>: M.Sc. Ahmed Omran, Abt. Quanten-Vielteilchensysteme / Dr. Michele Burrello, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 24.11.2015 14:30 - 16:00<br><strong>Summary</strong>: abstracts...Tue, 18 Oct 2016 10:56:20 +0200http://www.mpq.mpg.de/events/7241/5381003?14767809802016-10-18T10:56:20+02:00Nuclear structure from light muonic atoms (Dr. B. Franke) / LWFA-driven hard X-ray sources at LEX and CALA (K. Khrennikov)
http://www.mpq.mpg.de/events/7242/5381003
<strong>Speaker</strong>: Dr. Beatrice Franke, MPQ, Laser Spectroscopy Division / M.Sc. Konstantin Khrennikov, MPQ, Attosecond Physics Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.12.2015 14:30 - 16:00<br><strong>Summary</strong>: abstracts...Tue, 18 Oct 2016 10:55:05 +0200http://www.mpq.mpg.de/events/7242/5381003?14767809052016-10-18T10:55:05+02:00Attosecond ionization time delays (Prof. U. Keller)
http://www.mpq.mpg.de/events/7220/5381003
<strong>Speaker</strong>: Professor Dr. Ursula Keller, ETH Zürich, Switzerland<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 30.06.2015 14:30 - 16:00<br><strong>Summary</strong>: In a recent workshop we tried to answer the very interesting question: “Attosecond science – what will it take to observe processes ‘in real time’?” [1]. Tue, 18 Oct 2016 10:46:17 +0200http://www.mpq.mpg.de/events/7220/5381003?14767803772016-10-18T10:46:17+02:00Diversity, discrimination, and respect at work (Prof. S. Giessner)
http://www.mpq.mpg.de/events/7223/5381003
<strong>Speaker</strong>: Professor Dr. Steffen R. Giessner, Erasmus University Rotterdam, The Netherlands<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.07.2015 14:30 - 16:00<br><strong>Summary</strong>: This talk will give a short overview of the latest insights into the promises and pitfalls of a diverse workforce on employee outcomes like respectful interactions at work, cooperation, creativity and conflict at work. Mon, 17 Oct 2016 15:09:03 +0200http://www.mpq.mpg.de/events/7223/5381003?14767097432016-10-17T15:09:03+02:00(Un-)decidable problems in quantum theory (Prof. M. Wolf)
http://www.mpq.mpg.de/events/7236/5381003
<strong>Speaker</strong>: Prof. Dr. Michael Wolf, Zentrum Mathematik, M5, Technische Universität München<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.10.2015 14:30 - 16:00<br><strong>Summary</strong>: In the talk I will review recent results on the (un-)decidability of problems in quantum many-body physics and quantum information theory. Mon, 17 Oct 2016 14:50:40 +0200http://www.mpq.mpg.de/events/7236/5381003?14767086402016-10-17T14:50:40+02:00Novel ultra-fast and nanoscale opto-electronic phenomena in 2d material heterostructures (Prof. F. Koppens)
http://www.mpq.mpg.de/events/7237/5381003
<strong>Speaker</strong>: Prof. Dr. Frank Koppens, ICFO, The Institute of Photonic Sciences (Barcelona)<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 27.10.2015 14:00 - 16:00<br><strong>Summary</strong>: The optoelectronic response of two-dimensional (2D) crystals, such as graphene and transition metal dichalcogenides (TMDs), is currently subject to intensive investigations. Mon, 17 Oct 2016 14:49:59 +0200http://www.mpq.mpg.de/events/7237/5381003?14767085992016-10-17T14:49:59+02:00Physics beyond the standard model from molecules (Prof. W. Ubachs)
http://www.mpq.mpg.de/events/7238/5381003
<strong>Speaker</strong>: Prof. Dr. Wim Ubachs, Department of Physics and Astronomy, VU University, Amsterdam, Netherlands<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.11.2015 14:30 - 16:00<br><strong>Summary</strong>: The spectrum of molecular hydrogen H2 can be measured in the laboratory to very high precision using advanced laser and molecular beam techniques, as well as frequency-comb based calibration. Mon, 17 Oct 2016 14:48:00 +0200http://www.mpq.mpg.de/events/7238/5381003?14767084802016-10-17T14:48:00+02:00Sub-Cycle Quantum Physics (Prof. A. Leitenstorfer)
http://www.mpq.mpg.de/events/7252/5381003
<strong>Speaker</strong>: Prof. Dr. Alfred Leitenstorfer, Universität Konstanz, Fachbereich Physik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 06.11.2015 14:30 - 16:00<br><strong>Summary</strong>: Recent progress in establishing an extreme time-domain approach to condensed-matter physics and quantum optics is presented. Mon, 17 Oct 2016 14:47:10 +0200http://www.mpq.mpg.de/events/7252/5381003?14767084302016-10-17T14:47:10+02:00Simplex sigillum veri: Single atoms may settle quantum queries (Prof. P. Toschek)
http://www.mpq.mpg.de/events/7239/5381003
<strong>Speaker</strong>: Prof. Dr. Peter E. Toschek, Institut für Laser-Physik, Universität Hamburg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.11.2015 14:30 - 16:00<br><strong>Summary</strong>: Modern atomism evolved on the basis of observations of matter’s macroscopic features. Mon, 17 Oct 2016 14:46:04 +0200http://www.mpq.mpg.de/events/7239/5381003?14767083642016-10-17T14:46:04+02:00Quantum-information processing with solid-state single-photon sources (Prof. P. Lodahl)
http://www.mpq.mpg.de/events/7240/5381003
<strong>Speaker</strong>: Prof. Dr. Peter Lodahl, Niels Bohr Institute, University of Copenhagen, Denmark<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.11.2015 14:30 - 16:00<br><strong>Summary</strong>: We review the recent experimental progress on the use of quantum dots coupled to photonic-crystal waveguides [1]. Mon, 17 Oct 2016 14:44:11 +0200http://www.mpq.mpg.de/events/7240/5381003?14767082512016-10-17T14:44:11+02:00New Perspectives on Quantum Simulation with Alkaline-Earth Atoms (Prof. A. Rey)
http://www.mpq.mpg.de/events/7243/5381003
<strong>Speaker</strong>: Prof. Dr. Ana Maria Rey, JILA, NIST and University of Colorado, Boulder, CO 80309-0440, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 01.12.2015 14:30 - 16:00<br><strong>Summary</strong>: Understanding the behavior of interacting electrons in solids or liquids is at the heart of modern quantum science and necessary for technological advances. Mon, 17 Oct 2016 14:25:10 +0200http://www.mpq.mpg.de/events/7243/5381003?14767071102016-10-17T14:25:10+02:00Quantum mechanics at macroscopic scales (Prof. M. Kasevich)
http://www.mpq.mpg.de/events/7244/5381003
<strong>Speaker</strong>: Prof. Dr. Mark Kasevich, Department of Physics, Stanford University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.12.2015 14:30 - 16:00<br><strong>Summary</strong>: Quantum mechanics is a foundation of physics, chemistry and materials science. Still, there is an ongoing debate about the emergence of the classical, macroscopic world from the well-understood microscopic world of quantum mechanics. Mon, 17 Oct 2016 14:22:41 +0200http://www.mpq.mpg.de/events/7244/5381003?14767069612016-10-17T14:22:41+02:00Hundred years after general relativity: Was Einstein right? (Prof. M. Kramer)
http://www.mpq.mpg.de/events/7245/5381003
<strong>Speaker</strong>: Prof. Dr. Michael Kramer, MPI für Radioastronomie, Bonn<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.01.2016 14:30 - 16:00<br><strong>Summary</strong>: Hundred years after General Relativity: Was Einstein right? Mon, 17 Oct 2016 14:12:15 +0200http://www.mpq.mpg.de/events/7245/5381003?14767063352016-10-17T14:12:15+02:00Highly efficient organic devices (Prof. K. Leo)
http://www.mpq.mpg.de/events/7246/5381003
<strong>Speaker</strong>: Prof. Dr. Karl Leo, Institut für Angewandt Photophysik and Center for Advancing Electronic Devices (cfaed)<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 19.01.2016 14:30 - 16:00<br><strong>Summary</strong>: Organic semiconductors with conjugated electron system are currently intensively investigated for (opto-) electronics. Mon, 17 Oct 2016 14:08:59 +0200http://www.mpq.mpg.de/events/7246/5381003?14767061392016-10-17T14:08:59+02:00It’s All About Water (Prof. P. Hamm)
http://www.mpq.mpg.de/events/7247/5381003
<strong>Speaker</strong>: Prof. Dr. Peter Hamm, University of Zürich, Schweiz<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.01.2016 14:30 - 16:00<br><strong>Summary</strong>: Ultrafast time-resolved spectroscopy, and in particular its extension to multidimensional techniques, can tell us a lot about solvation dynamics, structural dynamics and energy transfer processes of solution phase molecular systems.Mon, 17 Oct 2016 14:04:55 +0200http://www.mpq.mpg.de/events/7247/5381003?14767058952016-10-17T14:04:55+02:00Topological photonics with twisted resonators and braided circuits (Prof. J. Simon)
http://www.mpq.mpg.de/events/7248/5381003
<strong>Speaker</strong>: Prof. Dr. Jonathan Simon, University of Chicago, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 02.02.2016 14:30 - 16:00<br><strong>Summary</strong>: I will present recent work realizing topological phases of photons. Mon, 17 Oct 2016 14:00:41 +0200http://www.mpq.mpg.de/events/7248/5381003?14767056412016-10-17T14:00:41+02:00Microscopy 2.0 (Prof. S. Chu)
http://www.mpq.mpg.de/events/7249/5381003
<strong>Speaker</strong>: Prof. Dr. Steven Chu, Stanford University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.02.2016 14:30 - 16:00<br><strong>Summary</strong>: There has been an explosion of new imaging technologies in biology that include photo-activation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), and stimulated emission depletion (STED), structured illumination, and adaptive optics are revolutionizing optical microscopy. Mon, 17 Oct 2016 13:59:48 +0200http://www.mpq.mpg.de/events/7249/5381003?14767055882016-10-17T13:59:48+02:00Linking high harmonics from solids and gases (Prof. P. Corkum)
http://www.mpq.mpg.de/events/7250/5381003
<strong>Speaker</strong>: Prof. Dr. Paul Corkum, Joint Attosecond Science Lab, University of Ottawa and National Research Council of Canada, Ottawa, Canada<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.03.2016 14:30 - 16:00<br><strong>Summary</strong>: Attosecond pulses are generated by electrons that are extracted from a quantum system by an intense light pulse and travel through the continuum. Mon, 17 Oct 2016 13:57:11 +0200http://www.mpq.mpg.de/events/7250/5381003?14767054312016-10-17T13:57:11+02:00Entanglement of Complex Quantum Systems (Prof. N. Schuch)
http://www.mpq.mpg.de/events/7264/5381003
<strong>Speaker</strong>: Prof. Dr. N. Schuch, MPQ, Theory Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.04.2016 14:30 - 16:00<br><strong>Summary</strong>: Complex quantum systems exhibit a variety of unconventional phenomena, such as protected quantized edge currents or excitations with non-trivial statistics. Mon, 17 Oct 2016 13:46:09 +0200http://www.mpq.mpg.de/events/7264/5381003?14767047692016-10-17T13:46:09+02:00The device-independent scenario: a quantum information theory with black boxes (Prof. A. Acin)
http://www.mpq.mpg.de/events/7266/5381003
<strong>Speaker</strong>: Prof. Dr. Antonio Acin, ICFO Barcelona, Spain<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.04.2016 14:30 - 16:00<br><strong>Summary</strong>: Device-independent quantum information processing represents a new framework for quantum information applications in which devices are just seen as quantum black boxes processing classical information. Mon, 17 Oct 2016 13:41:22 +0200http://www.mpq.mpg.de/events/7266/5381003?14767044822016-10-17T13:41:22+02:00Metasurfaces for Wavefront Shaping: High-performance Planar Photonic Components beyond Refractive and Diffractive Optics (Prof. F. Capasso)
http://www.mpq.mpg.de/events/7267/5381003
<strong>Speaker</strong>: Prof. Dr. Federico Capasso, Harvard School of Engineering and Applied Sciences<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.05.2016 14:30 - 16:00<br><strong>Summary</strong>: The design of fundamental optical components such as lenses, gratings, and holograms has remained essentially unchanged for at least fifty years, relying on textbook refractive and diffractive optics. Mon, 17 Oct 2016 13:39:12 +0200http://www.mpq.mpg.de/events/7267/5381003?14767043522016-10-17T13:39:12+02:00Synthetic gauge fields in synthetic dimensions: Magnetic crystals and chiral edge modes (Prof. R. Fazio)
http://www.mpq.mpg.de/events/7268/5381003
<strong>Speaker</strong>: Prof. Dr. Rosario Fazio, ICTP Triest, Italy<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.05.2016 14:30 - 16:00<br><strong>Summary</strong>: Synthetic ladders realized with one-dimensional alkaline-earth(-like) fermionic gases and subject to a gauge field represent a promising environment for the investigation of quantum Hall physics with ultracold atoms. Mon, 17 Oct 2016 13:36:04 +0200http://www.mpq.mpg.de/events/7268/5381003?14767041642016-10-17T13:36:04+02:00Aspects of Topological Photonics (Prof. M. Rechtsman)
http://www.mpq.mpg.de/events/7269/5381003
<strong>Speaker</strong>: Prof. Dr. Mikael Rechtsman, Penn State University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.05.2016 14:30 - 16:00<br><strong>Summary</strong>: The beauty of topological materials is that their electronic properties can be essentially described by integer topological invariants associated with their band structures. Mon, 17 Oct 2016 13:35:17 +0200http://www.mpq.mpg.de/events/7269/5381003?14767041172016-10-17T13:35:17+02:00How to catch, and detect, a photon (Prof. W. Tittel)
http://www.mpq.mpg.de/events/7270/5381003
<strong>Speaker</strong>: Prof. Dr. Wolfgang Tittel, Institute for Quantum Science and Technology, and Department of Physics & Astronomy, University of Calgary, Canada<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.05.2016 11:00 - 13:00<br><strong>Summary</strong>: Future quantum networks will allow the secure distribution of encryption keys over extended distances, blind quantum computing, and networked quantum computers and atomic clocks. Mon, 17 Oct 2016 13:33:45 +0200http://www.mpq.mpg.de/events/7270/5381003?14767040252016-10-17T13:33:45+02:00Quantum metrology with Bose Einstein Condensates (Prof. M. Oberthaler)
http://www.mpq.mpg.de/events/7271/5381003
<strong>Speaker</strong>: Prof. Dr. Markus Oberthaler, Kirchhoff-Institut für Physik, Universität Heidelberg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 31.05.2016 14:30 - 15:30<br><strong>Summary</strong>: One aspect of metrology, the science of measurement, is the exploration of the ultimate precision limit. It is known for quite some time that the new possibilities in quantum mechanics allow the surpassing of the ultimate classical precision limit given by counting statistics. Mon, 17 Oct 2016 13:30:00 +0200http://www.mpq.mpg.de/events/7271/5381003?14767038002016-10-17T13:30:00+02:00Ultrafast dynamics of spins and spin currents: magnetic storage and spintronic THz emitter (Prof. M. Münzenberg)
http://www.mpq.mpg.de/events/7272/5381003
<strong>Speaker</strong>: Prof. Dr. Markus Münzenberg, Department of Physics, Ernst-Moritz-Arndt-University, Greifswald<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.06.2016 14:30 - 15:30<br><strong>Summary</strong>: Magnetization manipulation is an indispensable tool for both basic and applied research. I will discuss some of the knobs to tune dynamics at ultrafast time scales. Mon, 17 Oct 2016 13:28:38 +0200http://www.mpq.mpg.de/events/7272/5381003?14767037182016-10-17T13:28:38+02:00Wavefront Shaping and the Control of Scattering (Prof. Y. Silberberg)
http://www.mpq.mpg.de/events/7276/5381003
<strong>Speaker</strong>: Prof. Dr. Yaron Silberberg, Weizman Institute of Science, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.06.2016 14:30 - 15:30<br><strong>Summary</strong>: The propagation of light in inhomogeneous media, and in particular in biological tissues, results in wavefront distortions and scattering which impose major limitations in many applications, from microscopy to nanosurgery. Mon, 17 Oct 2016 13:20:06 +0200http://www.mpq.mpg.de/events/7276/5381003?14767032062016-10-17T13:20:06+02:00The Quantum Way of Sensing (Prof. J. Wrachtrup)
http://www.mpq.mpg.de/events/7274/5381003
<strong>Speaker</strong>: Prof. Dr. Jörg Wrachtrup, University of Stuttgart, 3rd Physics Institute and Center for Integrated Quantum Science and Technology IQST<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 05.07.2016 14:30 - 15:30<br><strong>Summary</strong>: The precision of any measurement is limited by quantum mechanics. Yet, in practice, hardly any measurement reaches its quantum limits. This is because dephasing typically influences measurement device, rendering their sensitivity below its physical limits. Mon, 17 Oct 2016 13:19:14 +0200http://www.mpq.mpg.de/events/7274/5381003?14767031542016-10-17T13:19:14+02:00LIGO’s detection of gravitational waves from a binary black hole merger (Dr. P. Fritschel)
http://www.mpq.mpg.de/events/7275/5381003
<strong>Speaker</strong>: Dr. Peter K. Fritschel, MIT KAVli Institute for Astrophysics AND Space Research, Massachusetts, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.07.2016 15:30 - 16:30<br><strong>Summary</strong>: On September 14, 2015 the two LIGO gravitational wave detectors in Hanford, Washington and Livingston, Louisiana registered a coincident signal conforming to the gravitational waveform expected from the merger of two massive, compact objects. Mon, 17 Oct 2016 12:27:22 +0200http://www.mpq.mpg.de/events/7275/5381003?14767000422016-10-17T12:27:22+02:00Coherence of a Bose-Einstein Condensed Light Field (Prof. M. Weitz)
http://www.mpq.mpg.de/events/7277/5381003
<strong>Speaker</strong>: Prof. Dr. Martin Weitz, Institut für Angewandte Physik, Universität Bonn<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.07.2016 14:30 - 15:30<br><strong>Summary</strong>: Bose-Einstein condensation has been observed with cold atomic gases, quasiparticles in solid state systems as polaritons, and more recently with photons in a dye-filled optical microcavity. Mon, 17 Oct 2016 12:26:29 +0200http://www.mpq.mpg.de/events/7277/5381003?14766999892016-10-17T12:26:29+02:00Quantum plasmonics, polaritons and strong light-matter interactions with 2d material heterostructures (Prof. F. Koppens)
http://www.mpq.mpg.de/events/7292/5381003
<strong>Speaker</strong>: Prof. Dr. Frank Koppens , ICFO Barcelona, Spain<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 02.11.2016 14:30 - 15:30<br><strong>Summary</strong>: The controlof polaritons are at the heart of nano-photonics and opto-electronics. Two-dimensional materials have emerged as a toolbox for in-situ control of awide range of polaritons: plasmons, excitons and phonons.Mon, 17 Oct 2016 12:05:35 +0200http://www.mpq.mpg.de/events/7292/5381003?14766987352016-10-17T12:05:35+02:00Driven-dissipative Bose-Einstein condensates (Prof. H. Ott)
http://www.mpq.mpg.de/events/7293/5381003
<strong>Speaker</strong>: Prof. Dr. Herwig Ott, Department of Physics, Technische Universität Kaiserslautern<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.11.2016 14:30 - 15:30<br><strong>Summary</strong>: Ultracold quantum gases are usually well isolated from the environment. This allows for the study of ground state properties and unitary dynamics of many-body quantum systems under almost ideal conditions.Mon, 17 Oct 2016 12:03:31 +0200http://www.mpq.mpg.de/events/7293/5381003?14766986112016-10-17T12:03:31+02:00MAGIC with Trapped Ions (Prof. C. Wunderlich)
http://www.mpq.mpg.de/events/7295/5381003
<strong>Speaker</strong>: Prof. Dr. Christof Wunderlich, Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 22.11.2016 14:30 - 15:30<br><strong>Summary</strong>: Trapped atomic ions are a well-advanced physical system for quantum information science (QIS). QIS is meant to encompass the quest for a specialized, or even universal processor for quantum information, the investigation of fundamental questions of quantum physics, as well as applications of techniques emanating from these investigations to other fields, for example, precision spectroscopy and sensing.Mon, 17 Oct 2016 12:02:52 +0200http://www.mpq.mpg.de/events/7295/5381003?14766985722016-10-17T12:02:52+02:003D Printing of Complex Microoptics – Merging with Plasmonic Nanooptics (Prof. H. Giessen)
http://www.mpq.mpg.de/events/7298/5381003
<strong>Speaker</strong>: Prof. Dr. Harald Giessen, 4th Physics Institute, Universität Stuttgart<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.12.2016 14:30 - 15:30<br><strong>Summary</strong>: Microoptics has a plethora of applications, ranging from miniature endoscopes in hospitals to beam shaping or imaging. 3D printing with a femtosecond laser and two-photon polymerization allows for manufacturing optical elements directly after their design with an optical CAD program on a computer, with a resolution better than 100 nm and a high accuracy and reproducibility.Mon, 17 Oct 2016 11:52:30 +0200http://www.mpq.mpg.de/events/7298/5381003?14766979502016-10-17T11:52:30+02:00Nonlinear optics with ultra-broadband oscillators
http://www.mpq.mpg.de/events/7171/5381003
<strong>Speaker</strong>: Professor Uwe Morgner, Universität Hannover<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 01.07.2014 12:30<br><strong>Summary</strong>: "High repetition rate parametric oscillators and amplifiers (OPO, OPA) for very short optical pulses profit from the advancement in high power solid-state pump laser technology. In this talk, topical OPA and OPO systems with multi-Watt average powers and sub-10 fs pulses are presented. Employing (2+1)D nonlinear propagation simulation it is possible to reconstruct the complex spatio-temporal and spectral evolution of the interacting light fields and their mixing products in the gain crystals.Regarding the shortest pulses, challenges in pulse characterization and pulse shaping are addressed as well as some fundamental questions regarding the femtosecond response time of nonlinear phenomena."Thu, 03 Sep 2015 23:02:43 +0200http://www.mpq.mpg.de/events/7171/5381003?14413141632015-09-03T23:02:43+02:00Space-time circuit-to-Hamiltonian construction and its applications
http://www.mpq.mpg.de/events/7170/5381003
<strong>Speaker</strong>: Professor Barbara Terhal, Rheinisch-Westfälische Technische Hochschule Aachen<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.06.2014 12:30<br><strong>Summary</strong>: "The circuit-to-Hamiltonian construction translates dynamics (a quantum circuit and its output) into statics (the groundstate of a circuit Hamiltonian) by explicitly defining a quantum register for a clock. The standard Feynman-Kitaev construction uses one global clock for all qubits while we consider a different construction in which a clock is assigned to each interacting qubit. This makes it possible to capture the spatio-temporal structure of the original quantum circuit into features of the circuit Hamiltonian. The construction is inspired by the original two-dimensional interacting fermionic model (see this http URL) We prove that for one-dimensional quantum circuits the gap of the circuit Hamiltonian is appropriately lower-bounded so that the applications of this construction for QMA (and partially for quantum adiabatic computation) go through. For one-dimensional quantum circuits, the dynamics generated by the circuit Hamiltonian corresponds to diffusion of a string around the torus. See the paper at http://arxiv.org/abs/1311.6101"Thu, 03 Sep 2015 23:02:43 +0200http://www.mpq.mpg.de/events/7170/5381003?14413141632015-09-03T23:02:43+02:00Design of a superconducting quantum computer
http://www.mpq.mpg.de/events/7169/5381003
<strong>Speaker</strong>: Professor John Martinis, University of California<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.06.2014 12:30<br><strong>Summary</strong>: "Superconducting quantum computing is now at an important crossroad, where “proof of concept” experiments involving small numbers of qubits can be transitioned to more challenging and systematic approaches that could actually lead to building a quantum computer. Our optimism is based on two recent developments: a new hardware architecture for error detection based on “surface codes”, and recent improvements in the coherence of superconducting qubits. I will explain how the surface code is a major advance for quantum computing, as it allows one to use qubits with realistic fidelities, and has a connection architecture that is compatible with integrated circuit technology. Additionally, the surface code allows quantum error detection to be understood using simple principles. I will also discuss how the hardware characteristics of superconducting qubits map into this architecture, and review recent results that show gate errors can be reduced to below that needed for the error detection threshold."Thu, 03 Sep 2015 23:02:42 +0200http://www.mpq.mpg.de/events/7169/5381003?14413141622015-09-03T23:02:42+02:00Quantum life
http://www.mpq.mpg.de/events/7168/5381003
<strong>Speaker</strong>: Professor Seth Lloyd, Massachusetts Institute of Technology<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.06.2014 12:30<br><strong>Summary</strong>: "Recent experimental investigations of excitonic transport in photosynthesis indicate that quantum coherence can play an important role in enhancing energy transport in photosynthetic complexes.This talk presents a general theory of optimizing energy transport in photosynthesis and in artificial systems.Optimal energy transport takes place at the point where the timescales for dynamic and static disorder converge, a phenomenon called the quantum Goldilocks effect."Thu, 03 Sep 2015 23:02:42 +0200http://www.mpq.mpg.de/events/7168/5381003?14413141622015-09-03T23:02:42+02:00Qubits in diamond: solid state quantum registers and nanoscale sensors
http://www.mpq.mpg.de/events/7167/5381003
<strong>Speaker</strong>: Professor Fedor Jelezko, Universität Ulm, Institut für Quantenoptik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.06.2014 12:30<br><strong>Summary</strong>: "Recently, atom-like impurities in diamond (colour centres) have emerged as an exceptional system for quantum physics in solid state. In this talk I will discuss recent developments transforming quantum control tools into quantum technologies based on single colour centres. Specially, realization of quantum optical interface between spins and photons and scalable quantum registers in diamond will be presented. New applications of diamond qubits involving nanoscale magnetic resonance and force measurements will be shown. I will discuss single spin NMR paving the way to ultrasensitive MRI and structure determination of single biomolecules. The detection of proteins using nanodiamond sensors will be presented. I will also highlight future directions of research including combination of quantum error correction and sensing protocols and quantum enabled sensing and imaging in living cells."Thu, 03 Sep 2015 23:02:41 +0200http://www.mpq.mpg.de/events/7167/5381003?14413141612015-09-03T23:02:41+02:00Uniform Bose gases
http://www.mpq.mpg.de/events/7166/5381003
<strong>Speaker</strong>: Professor Zoran Hadzibabic, University of Cambridge, UK<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.05.2014 12:30<br><strong>Summary</strong>: "For almost two decades harmonically-trapped ultracold atomic gases have been used with great success to study fundamental many-body physics in a flexible experimental setting. Recently, we achieved the first atomic Bose-Einstein condensate in an essentially uniform potential of an optical-box trap [1]. This opens unprecedented possibilities for closer connections with other many-body systems and the textbook models that rely on the translational symmetry of the system. I will present our first experiments on this new system, including the first observation of the quantum Joule-Thomson effect [2], which was theoretically predicted more than 70 years ago.[1] A. L. Gaunt et al., Phys. Rev. Lett. 110, 200406 (2013)[2] T. F. Schmidutz et al., Phys. Rev. Lett. 112, 040403 (2014)"Thu, 03 Sep 2015 23:02:40 +0200http://www.mpq.mpg.de/events/7166/5381003?14413141602015-09-03T23:02:40+02:00Precision spectroscopy of atomic hydrogen for a new determination of the Rydberg Constant and the proton charge radius
http://www.mpq.mpg.de/events/7165/5381003
<strong>Speaker</strong>: Axel Beyer, Max Planck Institut für Quantenoptik, Abt. Laser-Spektroskopie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.05.2014 12:30<br><strong>Summary</strong>: "The comparison between experimental values of transition frequencies in atomic hydrogen, the most simple atomic system, and the corresponding theoretical predictions provides stringent tests of bound state QED calculations. For more than a decade, this comparison has been limited by insufficient knowledge about the size of the proton, strictly speaking its r.m.s. charge radius. In 2010, a value for the proton size has been extracted from laser spectroscopy of muonic hydrogen which is ten times more accurate than any previous determination. However, this value deviates from the value found by precision spectroscopy of regular hydrogen by four combined standard deviations. An even larger inconsistency of 7σ is obtained when including electron-proton scattering data. The muonic hydrogen value has been confirmed and improved in 2013 while the source of the discrepancy, referred to as the ‘proton size puzzle’, remains unclear.In this talk, we report on a new precision spectroscopy experiment, aiming to shed light on the regular hydrogen part of the puzzle: In contrast to previous high resolution experiments probing transition frequencies between the meta-stable 2S state and a higher lying nL state (n = 3, 4, 6, 8, 12, L = S, P, D), our measurement of the 2S – 4P transition frequency is the first experiment being performed on a cryogenic beam of hydrogen atoms in the 2S state. We will discuss how this helps to efficiently suppresses leading systematic effects of previous measurements and present preliminary results obtained so far."Thu, 03 Sep 2015 23:02:40 +0200http://www.mpq.mpg.de/events/7165/5381003?14413141602015-09-03T23:02:40+02:00Infinite-dimensional-matrix product states, topology, and criticality
http://www.mpq.mpg.de/events/7164/5381003
<strong>Speaker</strong>: Dr. Anne Ersbak Bang Nielsen, Max Planck Institut für Quantenoptik, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.05.2014 12:30<br><strong>Summary</strong>: "Strongly correlated quantum many-body systems display many fascinating phenomena, but they are difficult to describe due to the huge dimension of the involved Hilbert spaces. For this reason, models that can be treated fully or partially by analytical tools are valuable guides for understanding the physics underlying the phenomena. A prominent example is the fractional quantum Hall effect (FQHE), for which much information has been obtained by use of trial wave functions. In the talk, I will present a method to construct a quite broad class of many-body models, for which both the state and Hamiltonian are known analytically. One family of states within this class constitutes FQHE-like lattice states. The FQHE was originally discovered in semiconductor devices, but in the last few years much effort has been put into investigating the possibilities for obtaining FQHE-like states in lattice systems. One motivation for this is the perspectives for simulating FQHE physics under highly controllable conditions, e.g. in ultracold atoms or molecules in optical lattices. The typical strategy for obtaining FQHE-like lattice states is to mimic the solid state setting, but the above mentioned family of models provides an alternative. It is also possible to construct critical models, which allows us to study phase transitions."Thu, 03 Sep 2015 23:02:40 +0200http://www.mpq.mpg.de/events/7164/5381003?14413141602015-09-03T23:02:40+02:00Breaking dogmas with ultracold erbium atoms
http://www.mpq.mpg.de/events/7163/5381003
<strong>Speaker</strong>: Prof. Francesca Ferlaino, Universität Innsbruck, Institut für Experimentalphysik and Zentrum für Quantenphysik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.04.2014 12:30<br><strong>Summary</strong>: "Non-alkali-metal atoms have recently proved to be fascinating systems to explore novel lands in ultracold quantum physics. Here, we present recent results with ultracold dipolar gases of erbium atoms. As a consequence of the strong dipole-dipole interaction and of the large anisotropy in the dispersion potential, Er shows a spectacularly high number of Fano-Feshbach resonances both in the fermionic and bosonic isotopes. The complex Er scattering behavior escapes to traditional scattering models and requires novel approaches based on statistical analysis. Following the powerful toolset provided by Random-Matrix theory, we elucidate the chaotic nature of the scattering. Finally, we report on the first degenerate Fermi gas of Er, which is realized by direct cooling of identical fermions based on dipole-dipole interaction."Thu, 03 Sep 2015 23:02:39 +0200http://www.mpq.mpg.de/events/7163/5381003?14413141592015-09-03T23:02:39+02:00Entangled ions in an optical cavity
http://www.mpq.mpg.de/events/7162/5381003
<strong>Speaker</strong>: Dr. Tracy Northup, Universität Innsbruck<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 22.04.2014 12:30<br><strong>Summary</strong>: "Optical cavities provide a coherent interface between light and matter that can be used to link remote quantum systems. With such an interface, quantum information can be mapped from a single atom onto a photon for long-distance transport, and an atom can be entangled with a cavity photon as a resource for teleportation. However, in a future quantum network, it would be advantageous for each cavity to contain multiple atoms. These atoms could be used for local quantum information processing, error correction between network nodes, and improved quantum memories, among other tasks.I will describe the coupling of two calcium ions to the mode of a high-finesse optical cavity. When both ions are coupled with near-maximum strength to the cavity, we entangle the ions with one another, heralded by the measurement of two orthogonally polarized photons. Applications of entangled ions in a cavity will be discussed, in the context of both quantum information tasks and the investigation of open quantum systems. In particular, I will present recent measurements of enhanced quantum state transfer from a superradiant two-ion state."Thu, 03 Sep 2015 23:02:39 +0200http://www.mpq.mpg.de/events/7162/5381003?14413141592015-09-03T23:02:39+02:00Visualization of atomic and electronic motion in 4D
http://www.mpq.mpg.de/events/7161/5381003
<strong>Speaker</strong>: Dr. Peter Baum, Ludwig-Maximilians-Universität München, Lehrstuhl für Experimentalphysik - Laserphysik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.04.2014 12:30<br><strong>Summary</strong>: "On a fundamental level, chemical reactions and condensed-matter transformations are defined by the motion of atoms and electrons from initial to final conformations, typically along a complex reaction path involving ultrasmall and ultrafast dimensions. Here we report on our progress towards a full visualization of structural dynamics in space and time. After laser excitation, ultrashort electron pulses at 30-100 keV are diffracted with time delays and provide a pump-probe sequence of structural snapshots with atomic resolution. We solve the most essential problem for time resolution, Coulomb repulsion, by using single-electron pulses in combination with a microwave compressor. The so achieved 12-fs electron pulses (rms) are among the shortest worldwide and now provide access to the fastest phonons or molecular modes with atomic resolution. In order to further advance towards the regime of purely electronic motion, we apply the microwave compressor’s time-dependent fields for reshaping the single-electron phase space from the temporal into the energetic domain. The achievable pulse durations are shorter than optical light cycles, promising direct diffraction access to electronic motion with a resolution of picometers and attoseconds. We report our first proof-of-principle results and reflect on what discoveries we may expect to see."Thu, 03 Sep 2015 23:02:39 +0200http://www.mpq.mpg.de/events/7161/5381003?14413141592015-09-03T23:02:39+02:00Single-photon switch based on Rydberg Blockade
http://www.mpq.mpg.de/events/7160/5381003
<strong>Speaker</strong>: Simon Baur, Max Planck Institut für Quantenoptik, Abt. Quantendynamik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.04.2014 12:30<br><strong>Summary</strong>: "All-optical switching is a technique in which a gate light pulse changes the transmission of a target light pulse without the detour via electronic signal processing. We take this to the quantum regime, where the incoming gate light pulse contains only one photon on average. The gate pulse is stored as a Rydberg excitation in an ultracold atomic gas using electromagnetically induced transparency. Rydberg blockade suppresses the transmission of the subsequent target pulse. Finally, the stored gate photon can be retrieved. A retrieved photon heralds successful storage. The corresponding postselected subensemble shows an extinction of 0.05. Recent improvements of our experiment made it possible to observe a gain of 20. The single-photon switch offers many interesting perspectives ranging from quantum communication to quantum information processing."Thu, 03 Sep 2015 23:02:39 +0200http://www.mpq.mpg.de/events/7160/5381003?14413141592015-09-03T23:02:39+02:00A Physicist´s View of the German „Energiewende”
http://www.mpq.mpg.de/events/7159/5381003
<strong>Speaker</strong>: Professor Christoph Buchal, Forschungszentrum Jülich<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.04.2014 12:30<br><strong>Summary</strong>: "This talk discusses the ideas and goals of the Energiewende, which aims at successively decarbonizing all of the german energy supply systems, but suffers from patchwork, wild exaggerations, cost explosions, and true pitfalls due to the construction of the European Climate Program.After a general overview we have a closer look at the electrical power generation and distribution, which is strongly affected by the Energiewende. We evaluate the consequences of the intermittent power production by wind turbines and photovoltaic panels, the dynamics of the present conventional power plants and the need and potential of present or future storage systems. The role of hydrogen and synthetic fuels as a form of chemical energy storage is discussed."Thu, 03 Sep 2015 23:02:38 +0200http://www.mpq.mpg.de/events/7159/5381003?14413141582015-09-03T23:02:38+02:00"Quantum Theory from Quantum Information? (What would Feynman say?)"
http://www.mpq.mpg.de/events/7158/5381003
<strong>Speaker</strong>: Professor Christopher A. Fuchs, Perimeter Institute for Theoretical Physics, Canada<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.02.2014 12:30<br><strong>Summary</strong>: How did the field of quantum information begin? To my mind, it was when John Wheeler formed his little group of students and postdocs at the University of Texas in the early 1980s. David Deutsch, Benjamin Schumacher, William Wootters, and Wojciech Zurek were all there. Even Richard Feynman visited once. It was because Wheeler had a single-minded purpose. To every student who walked into his office---even the first year undergraduate---Wheeler would implore: “Give an information theoretic derivation of quantum theory!” He saw that as the only way to get a real understanding of “the quantum” (as he called it). In this talk, I will outline how Wheeler’s old hope is still giving technical fruit in the context of Quantum Bayesianism (or QBism). Particularly, that context points naturally to a study of a mysterious structure in Hilbert space called the Symmetric Information Complete (SIC) quantum measurement. When these structures exist (and it seems they do for all finite dimensions, though no one has yet proven it!) they give a very clean way of writing the Born rule in purely probabilistic terms. This gives the hope that all the mathematical structure of quantum theory might be derivable from one very basic physical scenario. It’s not the double-slit experiment that Feynman argued for in his Feynman Lectures, but one might still appeal to his foresight and hope, “In reality, [this new scenario] contains the only mystery [of quantum mechanics].”Thu, 03 Sep 2015 23:02:38 +0200http://www.mpq.mpg.de/events/7158/5381003?14413141582015-09-03T23:02:38+02:00"Spin orbit coupled atomic gases"
http://www.mpq.mpg.de/events/7157/5381003
<strong>Speaker</strong>: Professor Ian Spielman, Joint Quantum Institute (JQI), NIST Gaithersburg, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.02.2014 12:30<br><strong>Summary</strong>: Gauge fields are ubiquitous in Physics. For example, in the context of high energy physics, they are the fundamental carrier of forces; while in condensed matter systems the associated physical fields (electrical and magnetic) are essential in creating and understanding many-body phenomena. These fields can depend on internal — spin — degrees of freedom, and in material systems these spin-dependent gauge fields are often manifest as spin-orbit coupling (SOC, but more correctly spin-crystal momentum coupling).Here I present our experimental work synthesizing SOC for ultracold neutral atoms. I will first show how we use the light-matter interaction to engineer gauge terms in the atomic Hamiltonian, and then how to make these depend on spin. Using such techniques, we created SOC in a pseudo-spin 1/2 Bose gas and observed a previously unexpected quantum phase transition. I will conclude by showing the observed phase diagram of a spin-1 spin-orbit coupled Bose gas: a context without analog in traditional condensed matter systems. Thu, 03 Sep 2015 23:02:38 +0200http://www.mpq.mpg.de/events/7157/5381003?14413141582015-09-03T23:02:38+02:00"Attosecond light synthesis: New routes to PHz nonlinear control of matter"
http://www.mpq.mpg.de/events/7156/5381003
<strong>Speaker</strong>: Dr. Eleftherios Goulielmakis, Max-Planck Institut für Quantenoptik, Research Group "Attoelectronics"<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.01.2014 12:30<br><strong>Summary</strong>: Real-time control of electrons in the microcosm calls for electromagnetic forces confinable and tunable over sub-femtosecond time intervals. I will discuss how recent progress in lightwave technologies has enabled key steps towards this essential milestone in science and technology. With novel types of light synthesizers which can manipulate ultrawideband coherent radiation sources, spanning the visible and flanking spectral ranges, it is now possible to sculpt and trace the waveform of light with subcyclic precision opening up the route to attosecond photonics. We will focus on first representative applications that highlight the emerging capabilities. Thu, 03 Sep 2015 23:02:38 +0200http://www.mpq.mpg.de/events/7156/5381003?14413141582015-09-03T23:02:38+02:00"Cavity-enhanced single photon sources and scanning cavity microscopy with fiber-based optical microcavities"
http://www.mpq.mpg.de/events/7155/5381003
<strong>Speaker</strong>: Dr. David Hunger, Ludwig-Maximilians-Universität und Max-Planck Institut für Quantenoptik, Abt. Laserspektroskopie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.01.2014 12:30<br><strong>Summary</strong>: "Microscopic Fabry-Perot cavities built from laser-machined optical fibers offer small mode volumes and large quality factors combined with full tunability and direct access to the cavity field.In my talk I will present experiments where we harness these properties for enhanced light - matter interaction with solid-state based quantum- and nanosystems. Fiber cavities promise a route for efficient and narrow-band single-photon sources by means of Purcell enhancement of fluorescence emission. We couple colour centers in diamond nanocrystals such as the NV center to a cavity and study the scaling laws of the cavity enhancement for a large range of parameters. I will discuss our current efforts to achieve broadband enhancement with ultra-small mode volume cavities and to generate indistinguishable single photons under ambient conditions. In the context of microscopy, multiple interaction of probe light with a sample placed inside a microcavity promises an increase in sensitivity on the order of the cavity Finesse, which can reach values >10^5 for fiber cavities. We demonstrate a scheme for scanning cavity microscopy, which provides spatially and spectrally resolved maps of various optical properties of a sample with superior sensitivity. The method should enable studies of individual non-flourescent macromolecules and weakly absorbing nanoparticles."Thu, 03 Sep 2015 23:02:37 +0200http://www.mpq.mpg.de/events/7155/5381003?14413141572015-09-03T23:02:37+02:00"Light and disorder: from Anderson localization to hyper-transport and photonic topological insulators"
http://www.mpq.mpg.de/events/7154/5381003
<strong>Speaker</strong>: Professor Mordechai Segev, Technion, Haifa, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.01.2014 12:30<br><strong>Summary</strong>: "Photonic systems are naturally an excellent avenue to study fundamental concepts of waves' interactions, and many times lead to new discoveries. I will discuss Anderson localization of light, its exact opposite: hyper-transport (faster than ballistic) transport driven by fluctuating spatial disorder, and finally the recent breakthrough on photonic topological insulators. The emphasis will be on fundamental concepts, that are universal to all waves systems."Thu, 03 Sep 2015 23:02:37 +0200http://www.mpq.mpg.de/events/7154/5381003?14413141572015-09-03T23:02:37+02:00Quantum photonic networks: building large-scale quantum machines out of light
http://www.mpq.mpg.de/events/7153/5381003
<strong>Speaker</strong>: Professor Ian Walmsley, University of Oxford, UK<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.01.2014 14:00<br><strong>Summary</strong>: "Non-classical states of light enable new modes of new modes of communications, sensing and computation. A key objective of current research is the construction of a scalable photonic quantum network that will facilitate the preparation of distributed quantum correlations among light beams, and enable new quantum-enhanced applications. Such a network can be constructed by means of pure-state quantum light sources, linear optical operations, measurement by photodetectors, and storage in a photonic quantum memory. I will discuss recent progress in developing a scalable network using such components, and describe some recent applications in quantum simulation, communication and metrology."Thu, 03 Sep 2015 23:02:36 +0200http://www.mpq.mpg.de/events/7153/5381003?14413141562015-09-03T23:02:36+02:00"Sub cycle non-sequential double ionization and excitation processes of xenon with polarization gated pulses"
http://www.mpq.mpg.de/events/7152/5381003
<strong>Speaker</strong>: Professor Bernd Witzel, Université Laval, Canada: Centre d´optique, photonique et laser (COPL); Department of Physics, Engineering Physics and Optics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 16.12.2013 12:30<br><strong>Summary</strong>: "We have studied short pulse laser ionization (< 7 fs, 750 nm) and excitation with polarization-gated laser pulses. The laser pulse used is composed of a circular section at the beginning and the end of the pulse and an experimentally-defined linearly polarized central part. Due to quantum mechanics selection rules (Dm ±1), multiphoton excitation of Rydberg states with high angular momentum are only possible with linearly polarized light. We show that polarization gating allows us to study excitation and ionization with quasi sub-cycle laser pulses. The method allows us to determine the shortest temporal window needed for the excitation processes. We have used polarization gated pulses to measure non-sequential ionization as a function of the gate duration." Thu, 03 Sep 2015 23:02:36 +0200http://www.mpq.mpg.de/events/7152/5381003?14413141562015-09-03T23:02:36+02:00"Coherent control and manipulation of nanomechanical systems"
http://www.mpq.mpg.de/events/7151/5381003
<strong>Speaker</strong>: Professor Eva M. Weig, Universität Konstanz<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.12.2013 12:30<br><strong>Summary</strong>: "Nanomechanical resonators are freely suspended, vibrating bridges with nanoscale diameters. These nanostructures are receiving an increasing amount of attention, both in fundamental experiments addressing the foundations of quantum mechanics and in sensing applications, and show great promise as linking elements in future hybrid nanosystems. A realization of this potential is however based on the development of not only nanomechanical systems of high mechanical quality factor but also suitable control techniques. Here I will review recent progress towards these goals, focussing on dielectrically controlled pre-stressed silicon nitride string resonators. In particular I will address the dynamics of two strongly coupled nanomechanical modes which can be described as a classical two-level system, adopting the well-known Bloch sphere picture. Analogous to the coherent control of two-level systems in atoms, spin ensembles or quantum bits, electromagnetic pulse techniques are employed to demonstrate full Bloch sphere control via Rabi, Ramsey and Hahn echo experiments. Our experiments not only enable deep insights into the limiting mechanisms for decoherence in nanomechanics, but also open a pathway towards single phonon control after a series of ground-breaking experiments on ground state cooling and non-classical signatures of nanomechanical resonators in recent years."Thu, 03 Sep 2015 23:02:36 +0200http://www.mpq.mpg.de/events/7151/5381003?14413141562015-09-03T23:02:36+02:00"Nondestructive detection of an optical photon"
http://www.mpq.mpg.de/events/7150/5381003
<strong>Speaker</strong>: Andreas Reiserer, Max-Planck-Institut für Quantenoptik, Abt. Quantendynamik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.12.2013 12:30<br><strong>Summary</strong>: "We demonstrate a robust photon detector which does not rely on photon absorption. Instead, impinging light is reflected off an optical resonator containing a single atom in a superposition of two states. Upon reflection of a single photon, the phase of the superposition state is flipped, which unambiguously allows us to nondestructively detect the photon. The presented single-photon nonlinearity paves the way towards photonic quantum gates and the preparation of novel quantum states of light."Thu, 03 Sep 2015 23:02:36 +0200http://www.mpq.mpg.de/events/7150/5381003?14413141562015-09-03T23:02:36+02:00"Spatially ordered structures and coherent control in a two-dimensional Rydberg gas"
http://www.mpq.mpg.de/events/7149/5381003
<strong>Speaker</strong>: Peter Schauß, MPI Quantenoptik, Abt. Quanten-Vielteilchensysteme<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.12.2013 12:30<br><strong>Summary</strong>: "Rydberg atoms provide a way to achieve controlled long-range interactions in many-body systems. In our setup we implemented an optical detection technique for Rydberg atoms with sub-micron resolution, which allows for the measurement spatial correlations in strongly interacting collective states of Rydberg atoms. We prepare a two-dimensional system of ground state atoms in an optical lattice and laser couple them to a Rydberg state. The Rydberg atoms interact via the van der Waals force, which extends over approximately half the system size, thereby leading to strong correlations. Guided by numerical optimization we found laser sweeps that created self-organized many-body states with spatially ordered Rydberg excitations. The initial ground state atom configuration is crucial for the success of the sweeps. We developed a preparation technique based on local addressing in an optical lattice that allows for the preparation of sub-shot-noise initial atom numbers. The developed techniques might allow for the deterministic preparation of ordered fock states of Rydberg atoms and the investigation of their coherence properties."Thu, 03 Sep 2015 23:02:35 +0200http://www.mpq.mpg.de/events/7149/5381003?14413141552015-09-03T23:02:35+02:00"Landscapes of light – complex ordered and disordered photonic lattices for creating artificial and biophotonic structured matter"
http://www.mpq.mpg.de/events/7148/5381003
<strong>Speaker</strong>: Professor Cornelia Denz, University of Münster, Institute of Applied Physics, Germany<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.11.2013 12:30<br><strong>Summary</strong>: "Photonic lattices are created by the inference of light in a complex way, and therefore represent an enabling technology for diverse applications as trapping atoms or optically tweezing nanoparticles, patterning in holographic lithography, and creating artificial matter as photonic crystals. In my presentation, I will show that by tailoring complex light landscapes as e.g. nondiffracting, self-similar or vortex-bearing light fields, or by randomizing these light fields, the next generation of artificial functional materials can be created as well as novel light routing and localization schemes can take place in these optically-created structures. Moreover, these light fields open new horizons in optical micromanipulation of artificial and biophybrid nanorobots."Thu, 03 Sep 2015 23:02:35 +0200http://www.mpq.mpg.de/events/7148/5381003?14413141552015-09-03T23:02:35+02:00"Charge and lattice dynamics in ionic crystals mapped by femtosecond x-ray powder diffraction"
http://www.mpq.mpg.de/events/7147/5381003
<strong>Speaker</strong>: Professor Thomas Elsässer, Max-Born-Institut für Nichtlineare Optik und Kuzzeitspektroskopie, Berlin<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 19.11.2013 12:30<br><strong>Summary</strong>: "Charge relocations and atomic motions on ultrashort time scales play a key role for functional processes in condensed matter. X-ray diffraction methods with a femtosecond time resolution allow for spatially resolving transient structures and, in particular, spatial distributions of electrons, both being relevant for the structure-function relationships of crystalline materials. This talk provides an introduction into this exciting new field, combining experimental aspects with recent results on ultrafast electron and lattice motions in ionic crystals. Experiments with the photoexcited prototype material KDP (KH2PO4) reveal the interplay of lattice and charge motions which occur on distinctly different length scales. As a second example, the field-driven transfer of valence electrons between ions in a superposition of quantum states will be addressed for the materials LiBH4 and LiH. This fully reversible transfer mechanism makes a major contribution to the material’s optical polarizability."Thu, 03 Sep 2015 23:02:34 +0200http://www.mpq.mpg.de/events/7147/5381003?14413141542015-09-03T23:02:34+02:00"Driven dissipative quantum many-body physics with strongly interacting photons"
http://www.mpq.mpg.de/events/7146/5381003
<strong>Speaker</strong>: Professor Michael Hartmann, TUM & Heriot Watt University Edinburgh<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.11.2013 12:30<br><strong>Summary</strong>: "Light consists of photons, mass-less particles that do not interact with one another. Recent technological developments however give rise to structures with strong interactions between light and matter in multiple nodes of a network. These devices may enable us to drive photons into novel strongly correlated quantum many-body regimes. Interestingly, these may by studied in non-equilibrium scenarios where inevitable photon losses are constantly compensated by input drives. They thus give rise to an intriguing class of quantum many-body systems where instead of ground or thermal states one is interested in the still largely unexplored stationary states of their driven and dissipative dynamics.In this talk, I will present some of our recent approaches to this physics which consider networks of superconducting circuit cavities and discuss aspects of the phase diagrams for their stationary states."Thu, 03 Sep 2015 23:02:33 +0200http://www.mpq.mpg.de/events/7146/5381003?14413141532015-09-03T23:02:33+02:00"Disordered ultracold atoms"
http://www.mpq.mpg.de/events/7145/5381003
<strong>Speaker</strong>: Professor Massimo Inguscio, LENS, Università di Firenze & CNR, Italy<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 05.11.2013 12:30<br><strong>Summary</strong>: "Ultracold atoms trapped in disordered and quasi-disordered optical potentials are a remarkable tool for the investigation of fundamental mechanisms of conduction in disordered systems. Indeed, these atomic systems offer the possibility of accurately tuning the interactions between the particles, their mobility, the system dimensionality and the kind and amount of disorder. A review of experimental results will be presented, also including very recent experiments which have provided a clear scenario for the superfluid-insulator transition in interacting disordered bosons and the observation of a mobility edge in three-dimensional Anderson localization."Thu, 03 Sep 2015 23:02:32 +0200http://www.mpq.mpg.de/events/7145/5381003?14413141522015-09-03T23:02:32+02:00"Unexpected strong-field physics in laser filaments"
http://www.mpq.mpg.de/events/7144/5381003
<strong>Speaker</strong>: Professor Misha Ivanov, Imperial College London<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.10.2013 12:30<br><strong>Summary</strong>: "In this talk I will discuss two topics.First, I will describe an unexpected physical mechanism of 'lasing without inversion' during filamentation of femtosecond laser pulses in the air. Importantly, realization of this mechanism requires no special effort -- it happens almost without trying.Second, I will discuss the connection between hypothetical higher order Kerr effects and the emergence of the 'Kramers-Henneberger atom' and the 'bound states of a free electron' -- stable excited electronic states dressed by a strong laser field."Thu, 03 Sep 2015 23:02:32 +0200http://www.mpq.mpg.de/events/7144/5381003?14413141522015-09-03T23:02:32+02:00"Non equilibrium dynamical processes in finite and extended systems from a time-dependent density functional (TDDFT) perspective"
http://www.mpq.mpg.de/events/7143/5381003
<strong>Speaker</strong>: Professor Angel Rubio, Universidad del País Vasco UPV/EHU, Donostia, Spain<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.10.2013 11:30<br><strong>Summary</strong>: "In this talk we will review the recent advances within density-functional and many-body based schemes to describe spectroscopic properties of complex systems with special emphasis to modelling time and spatially resolved electron spectroscopies (including transient pump-probe techniques). Pros and cons of present functionals will be highlighted and provide insight in how to overcome those limitations by merging concepts from many-body perturbation theory and time-dependent density functional theory. We will discuss some of the theoretical approaches developed in the group (and under development) for the characterisation of matter out of equilibrium, the control material processes at the electronic level and tailor material properties, and master energy and information on the nanoscale to propose new devices with capabilities. We will focus on examples linked to the efficient conversion of light into electricity or chemical fuels ("artificial photosynthesis") and the design on new nanostructured based optoelectronic devices based on inorganic nanotubes, among others. The goal of the group activities in the long-run is to provide a detailed, efficient, and at the same time accurate microscopic approach for the ab-initio description and control of the dynamics of decoherence and dissipation in quantum many-body systems. With the help of quantum optimal control (QOC) theory and the mastery over spectroscopy we could direct the movement of electrons, selectively trigger chemical reactions and processes, and create new materials."Thu, 03 Sep 2015 23:02:32 +0200http://www.mpq.mpg.de/events/7143/5381003?14413141522015-09-03T23:02:32+02:00"An orchestra of light: advanced timing distribution and light wave synthesis"
http://www.mpq.mpg.de/events/7142/5381003
<strong>Speaker</strong>: Professor Franz X. Kärtner, Center for Free-Electron Laser Science (CFEL), Hamburg & MIT, Cambridge, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 16.10.2013 09:00<br><strong>Summary</strong>: "Kilometer scale free-electron lasers will reach their full potential in providing molecular movies if all laser and rf-sources involved in the facility can be timed and synchronized to at least 10-fs precision with scalability to potentially 100 attoseconds in the future. A set of ultrafast optical techniques for long-term stable femtosecond synchronization of large-scale X-ray free-electron lasers will be presented and performance scaling towards sub-femtsecond precision will be demonstrated. Sub-cycle optical waveforms with spectra spanning multiple octaves are desired for efficient attosecond pulse generation and multi-wavelength spectroscopy. It turns out that some of the techniques invented for large scale timing distribution can be used to coherently stich few-cycle optical pulses together. Progress towards a multi-Joule optical waveform synthesizer covering 500 Nanometer – 2.5 micrometers will be presented and potential applications are discussed."Thu, 03 Sep 2015 23:02:31 +0200http://www.mpq.mpg.de/events/7142/5381003?14413141512015-09-03T23:02:31+02:00“Exploring quantum limits to optical measurement with millimeter-scale drums.”
http://www.mpq.mpg.de/events/7141/5381003
<strong>Speaker</strong>: Prof. Cindy Regal, JILA Center for Atomic, Molecular, & Optical Physics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.07.2013 11:30<br><strong>Summary</strong>: "The pursuit of increasingly sensitive interferometric measurement of mechanical motion has played an important role in the history of quantum optics. In a continuous position measurement, one must ultimately confront the effect of quantum measurement backaction. The requirement to balance measurement imprecision with backaction forces results in a lower bound on sensitivity, the ‘standard quantum limit’. Decades ago many ideas for avoiding this 'limit' were studied in the context of the ultimate sensitivity of gravitational wave detection. However, it has proven difficult to realize interferometers actually limited by quantum backaction, which physically stems from the shot noise of radiation pressure. In recent years, there has been considerable progress in manipulating low-mass, high-frequency, and mechanically-isolated objects with radiation pressure. In our group we have developed a cryogenically-compatible Fabry-Perot cavity incorporating a millimeter-scale silicon-nitride membrane. In this talk, I present work in which we subject the membrane to a strong continuous position measurement and observe the shot noise of radiation pressure. Further, we demonstrate correlations between quantum fluctuations of the optical field and the mechanical motion and use these correlations to observe ponderomotive squeezing of light. Mechanical objects at quantum limits also hold promise for connecting disparate quantum resources, for example microwave and optical photons; I will describe initial work, in conjunction with Konrad Lehnert’s group at JILA, to combine our optomechanical device with an electromechanical interface. I will end with a brief update on our work to control motion at another scale, namely experiments with single neutral atoms in optical tweezers laser-cooled to their ground state."Thu, 03 Sep 2015 23:02:31 +0200http://www.mpq.mpg.de/events/7141/5381003?14413141512015-09-03T23:02:31+02:00"Harnessing Quantum Fluctuations: Attractive and Repulsive Casimir Forces and the Future of Nanomachines."
http://www.mpq.mpg.de/events/7140/5381003
<strong>Speaker</strong>: Prof. Federico Capasso, Harvard University, Cambridge, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 23.07.2013 11:30<br><strong>Summary</strong>: "Casimir forces are macroscopic manifestations of QED and can be designed by altering the shape and material of the interacting bodies. In addition to experiments on attractive and repulsive forces that emphasize this dependence, I will discuss a number of exotic yet –to-be-observed effects such as the vacuum torque, vacuum radiation from oscillating cavities and related phenomena. Casimir forces offer both limits and exciting opportunities for the operation of future Nano-ElectroMechanical-Systems (NEMS)." Thu, 03 Sep 2015 23:02:31 +0200http://www.mpq.mpg.de/events/7140/5381003?14413141512015-09-03T23:02:31+02:00"Plasmonic Beam Coupling and Shaping"
http://www.mpq.mpg.de/events/7139/5381003
<strong>Speaker</strong>: Prof. Federico Capasso, Harvard University, Cambridge, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.07.2013 07:30<br><strong>Summary</strong>: "A new class of plasmonic interfaces is presented which greatly expands the capability of plasmonics for science and technology. I will discuss: polarization controlled tunable directional coupling of surface plasmons (SP); holographic metasurfaces that generate broadband radially polarized beams, holographic vortex detectors and the generation for the first time of straight propagating diffraction less SP beams (cosine-Gauss beams and bottle beams). These findings have potential applications in quantum information processing, chip interconnects and nanoparticle trapping."Thu, 03 Sep 2015 23:02:31 +0200http://www.mpq.mpg.de/events/7139/5381003?14413141512015-09-03T23:02:31+02:00Plasma Wakefield Acceleration Experiments Using Self-modulated Particle Bunches
http://www.mpq.mpg.de/events/7138/5381003
<strong>Speaker</strong>: Patric Muggli, Max-Planck-Institut für Physik, München<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.07.2013 12:00<br><strong>Summary</strong>: "Acceleration of particles at high gradient is an intense research topic. Without new acceleration methods allowing for future accelerators to be of reasonable size and cost, accelerator-based high-energy physics may reach an end. Plasmas can sustain very large longitudinal electric fields that can travel at velocities close to the speed of light. Large energy gains where demonstrated for electrons in plasma-based accelerators driven by intense laser pulses or short electron bunches. Research on the beam-driven, plasma wakefield accelerator (PWFA) scheme is experiencing an increasing interest. This is motivated by the 42GeV energy gain in 85 cm of plasma (50GeV/m accelerating gradient) demonstrated at SLAC [Blumenfeld, Nature 445, 741 (2007)]. Current PWFA experiments focus on two aspects: first, on the production of high quality accelerated bunches (narrow energy spread, low emittance, etc.) for example at SLAC FACET; second, on a new scheme based on the transverse self-modulation of long particle bunches in dense plasmas to resonantly drive wakefields [Kumar, Phys. Rev. Lett. 104, 255003 (2010)]. After briefly introducing the PWFA and the recent results I will focus on the second aspect and begin by introducing the physics of the self-modulation instability (SMI). I will discuss initial experiments at the Brookhaven National Laboratory Accelerator Test Facility that have shown that long electron bunches do indeed drive multiple period wakefields. They also suggest that the seeding of the self-modulation instability is possible. After presenting these results, I will describe experiments that we are planning at SLAC-FACET to study the physics of the SMI of electron and positron bunches. This experimental program is known as E209. Then I will describe the AWAKE project that was recently approved at CERN. AWAKE will use the long SPS, 400GeV bunch with 3x10^11 protons and a 10m-long plasma to address the issues related to driving GeV/m accelerating gradients over large distances to accelerate electrons to high energies in a single plasma section. This experiment will operate at lower gradient than other plasma-based accelerators, but aims at avoiding the staged-acceleration necessary when using drivers (laser pulse or particle bunch) carrying small amounts of energy. The SPS bunch carries ~20kJ, while LHC bunches carry more than 100kJ, more than necessary to produce an ILC-like electron bunch (2x10^10 e -500GeV or ~1.6kJ)! Operating at lower plasma density and therefore with a larger accelerating structure also eases the injection process and the beams generation and alignment tolerances. The purpose of the presentation is to give an overview of the experimental programs we are developing while explaining the basic concepts."Thu, 03 Sep 2015 23:02:30 +0200http://www.mpq.mpg.de/events/7138/5381003?14413141502015-09-03T23:02:30+02:00"Flat optics with designer meta-surfaces"
http://www.mpq.mpg.de/events/7137/5381003
<strong>Speaker</strong>: Prof. Federico Capasso, Harvard University, Cambridge, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.07.2013 13:00<br><strong>Summary</strong>: "New degrees of freedom in optical design can be attained by introducing in the optical path phase discontinuities in addition to the usual propagation phase. This enables wavefront engineering with unprecedented flexibility, including a generalization of the classical laws of reflection and refraction and a wide variety of new planar optical components. These include aberration-free flat lenses and axicons, background free broadband wave platesand flat phase plates that create optical vortices."Thu, 03 Sep 2015 23:02:30 +0200http://www.mpq.mpg.de/events/7137/5381003?14413141502015-09-03T23:02:30+02:00"Measurement of the Planck Constant and the Revision of the SI."
http://www.mpq.mpg.de/events/7136/5381003
<strong>Speaker</strong>: Prof. Stephan Schlamminger, University of Washington / NIST Gaithersburg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.07.2013 09:00<br><strong>Summary</strong>: "A revision of our system of units, the SI, is currently discussed and may be implemented as early as 2018. The new SI is a logical extension of an argument made in 1983 when the meter was redefined to be based on the exact value of the speed of light. In the new SI all units will be derived from seven fundamental reference constants, thus replacing the seven base units of the current system.For example, the unit of mass, the kilogram, is currently defined by an artifact called the International Prototype of the Kilogram (IPK). In the future we will be able to realize the unit of mass, not just at the kilogram level, from a fixed value of the Planck constant, which has units of kg m^2/s.One condition for redefinition is agreement between different measurements of the Planck constant. Currently two measurement strategies lead to values with relative uncertainties less than 100 parts per billion (ppb): (1) Avogadro’s number can be determined by estimating the number of atoms in a well characterized crystal. From Avogadro’s number h can be calculated using the Rydberg constant, which is known with much smaller uncertainty (2) A watt balance can be used to measure mechanical power in units of electrical power. Electrical power can be measured as the product of the Planck constant and two frequencies by utilizing the Josephson effect and the Quantum Hall effect.NIST has carried out measurements of h with watt balances for over 20 years. In the past 18 months a new team has performed a largely independent determination of h. I will describe this measurement and measurements from other laboratories."Thu, 03 Sep 2015 23:02:30 +0200http://www.mpq.mpg.de/events/7136/5381003?14413141502015-09-03T23:02:30+02:00"Cold Molecules: Science and Applications."
http://www.mpq.mpg.de/events/7135/5381003
<strong>Speaker</strong>: Prof. John Doyle, Harvard University, Cambridge, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.07.2013 11:30<br><strong>Summary</strong>: "Cold molecules are useful for doing science that ranges from fundamental particle physics to commercially important applications. I will discuss two experiments, the search for the electric dipole moment of the electron and determination of molecular identity within a mixture.We have developed methods for trace detection of molecules in mixtures, in both the optical and microwave regime. The cooling of the molecules leads to dramatic increase in the inverse of the internal molecular ro-vibrational partition function.In addition to species identification, we have also devised a method to measure the absolute chirality of the molecular species, and enantiomeric excess. We have recently demonstrated true sum-frequency generation, a type of three-wave mixing, on a chiral sample in the microwave regime. We use two orthogonally polarized resonant applied electric fields to induce a third mutually orthogonal field at their sum frequency. The phase of this induced field changes sign with enantiomer, and its amplitude provides a sensitive, quantitative measure of enantiomeric excess. The narrow rotational resonances used make this measure of enantiomeric excess fundamentally mixture compatible.In separate work, we have devised a new kind of high flux molecular beam and used it with ThO to perform a sensitive search for the electron EDM. Measurement of a non-zero electric dipole moment (EDM) of the electron within a few orders of magnitude of the current best limit[1] of |de|<1.05*10-27 e*cm would be an indication of CP violation beyond the Standard Model.The ACME Collaboration is searching for an electron EDM by performing a precision measurement of electron spin precession signals from the metastable H state of thorium monoxide (ThO). I will provide a brief update on the current status of the experiment. Based on a data set acquired from 50 hours of running time over a period of two days, we have achieved a one-sigma statistical uncertainty of 6*10-29 e*cm/√T, where T is the running time in days." [1] JJ Hudson et al., "Improved measurement of the shape of the electron." Nature 473, 493 (2011)Thu, 03 Sep 2015 23:02:29 +0200http://www.mpq.mpg.de/events/7135/5381003?14413141492015-09-03T23:02:29+02:00"From Scratch: A complete dynamical system based model of the peripheral auditory system"
http://www.mpq.mpg.de/events/7134/5381003
<strong>Speaker</strong>: Prof. Ruedi Stoop, Institute of Neuroinformatics (INI), ETH Zürich<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 05.07.2013 14:00<br><strong>Summary</strong>: "Pitch is a complex hearing phenomenon that results from elicited and self-generated cochlear vibrations. Read-off vibrational information is relayed up the auditory pathway, where it is then condensed into pitch sensation. How this can adequately be described in terms of physics has largely remained an open question. We have developed a peripheral hearing system (in hardware and software) that reproduces with great accuracy all salient pitch features known from biophysical and psychoacoustic experiments. At the level of the auditory nerve, the system exploits stochastic resonance to achieve this performance, which may explain the large amount of noise observed in the working auditory nerve. The work is a rare example of how starting from a general principle of physics, biological processes can be understood, and, moreover, lean and efficient sensory designs can be achieved by navigating close to the biophysical example. This in contrast to often-taken reverse engineering approaches that focus on modeling the resulting signal rather than asking on what physical grounds the resulting signal dwells."Thu, 03 Sep 2015 23:02:29 +0200http://www.mpq.mpg.de/events/7134/5381003?14413141492015-09-03T23:02:29+02:00"Ultrafast Optical and Terahertz Effects in Semiconductor Nanostructures."
http://www.mpq.mpg.de/events/7133/5381003
<strong>Speaker</strong>: Prof. Stephan Koch, Universität Marburg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 02.07.2013 11:30<br><strong>Summary</strong>: "Resonant optical excitation of semiconductors creates an interband polarization that can decay via re-radiation or interaction-induced conversion into quasi-particle excitations such as electron-hole plasma and/or excitons. With the help of time-delayed pulses with central frequencies in the terahertz (THz) range, one can induce transitions between the eigenstates of the temporally developing many-body system. Besides the characterization of the momentary excitation state, this combined optical and THz time-domain scheme allows for deliberate quantum-state manipulation, excitation shelving into optically dark states, transient exciton ionization, as well as high-harmonic generation."Thu, 03 Sep 2015 23:02:29 +0200http://www.mpq.mpg.de/events/7133/5381003?14413141492015-09-03T23:02:29+02:00"Attosecond electron dynamics in solids."
http://www.mpq.mpg.de/events/7132/5381003
<strong>Speaker</strong>: Prof. Reinhard Kienberger, Technische Universität München & Max-Planck-Institut für Quantenoptik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 25.06.2013 11:30<br><strong>Summary</strong>: After the full characterization of the tools for attosecond spectroscopy by the attosecond streaking technique [1], first experiments have been carried out to measure sub-femtosecond behavior of matter. Recently, the dynamics of the photoionization process on solids has been studied [2,3]. Not only that attosecond metrology now enables clocking on surface dynamics, but also the individual behaviour of electrons of different type (core electrons vs. conduction band electrons) can be resolved. We measured different time delays in the emission of the aforemention two types of electrons in different solids. Recent experiments towards an absolute measurement of the travel time of electron inside solids and through layered systems are discussed.On the other hand, experiments with molecules in the gas phase and on surfaces are carried out. UV pump / XUV probe experiments to investigate ultrafast electron dynamics in these molecules are introduced. [1] R. Kienberger et al., Nature 427, 817 (2004)[2] A. Cavalieri et al., Nature 449, 1029 (2007)[3] S. Neppl et al., PRL 109 (8), 087401 (2012)Thu, 03 Sep 2015 23:02:29 +0200http://www.mpq.mpg.de/events/7132/5381003?14413141492015-09-03T23:02:29+02:00"Molecular spectroscopy with laser frequency combs."
http://www.mpq.mpg.de/events/7131/5381003
<strong>Speaker</strong>: Dr. Nathalie Picqué, Max-Planck-Institut für Quantenoptik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 25.06.2013 11:30<br><strong>Summary</strong>: "The regular pulse train of a mode-locked femtosecond laser can give rise to a comb spectrum of millions of laser modes with a spacing precisely equal to the pulse repetition frequency. Laser frequency combs were conceived a decade ago as tools for the precision spectroscopy of atomic hydrogen. They are now becoming enabling tools for an increasing number of applications, including molecular spectroscopy. Recent experiments of multi-heterodyne frequency comb Fourier transform spectroscopy (also called dual-comb spectroscopy) have demonstrated that the spectral lines of a laser frequency comb can be harnessed for new techniques of linear absorption spectroscopy. The first proof-of-principle experiments have demonstrated a very exciting potential of dual-comb spectroscopy without moving parts for ultra-rapid and ultra-sensitive recording of complex broad spectral bandwidth molecular spectra. Compared to conventional Michelson-based Fourier transform spectroscopy, recording times could be shortened from seconds to microseconds, with intriguing prospects for spectroscopy of short lived transient species. The resolution improves proportionally to the measurement time. Therefore longer recordings allow high resolution spectroscopy of molecules with extreme precision, since the absolute frequency of each comb line can be known with the accuracy of an atomic clock. Moreover, since laser frequency combs involve intense ultrashort laser pulses, nonlinear interactions can be harnessed. Broad spectral bandwidth ultra-rapid nonlinear spectroscopy and imaging with two laser frequency combs is demonstrated with coherent Raman effects and two-photon excitation. Real-time multiplex accessing of hyperspectral images may dramatically expand the range of applications of nonlinear microscopy."Thu, 03 Sep 2015 23:02:28 +0200http://www.mpq.mpg.de/events/7131/5381003?14413141482015-09-03T23:02:28+02:00"Innovative Actuators for Advanced Mechatronics and Instrumentation."
http://www.mpq.mpg.de/events/7130/5381003
<strong>Speaker</strong>: Prof. Toshiro Higuchi, University of Tokyo, Department of Precision Engineering<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.06.2013 12:30<br><strong>Summary</strong>: "Applications of actuators have increased in various fields. In industry, precise and high speed positioning is one of the most important technologies. Especially in the production of semiconductors and flat panel displays, dust-free transporting and precise positioning systems for wafers and thin glass plates are needed to avoid generation of dusts. In peripheral machines for computers like disc memories, small and thin linear actuators are necessary to satisfy the demand of reduction of thickness and weight of the products.Conventional motors driven by the electromagnetic force will play the most important roles. However, in some cases these conventional actuators seem to be difficult to satisfy the new and advanced demands in the near future. Therefore, seeking for new actuators has been activated.Our laboratory in the University of Tokyo has been enrolled to develop new actuators of various kinds in order to cope with severe demands of coming production systems and future automated machines. In our laboratory, a number of unique actuators and drive technologies were invented and realized. Among them, first, the following two actuators using piezoelectric materials, impact drive mechanism and surface acoustic wave motor, are introduced with applications. Impact drive method can move an object with a step of several nm to micrometers for a long distance by using rapid deformation of a piezoelectric element. The surface acoustic wave motor is a very thin ultrasonic motor with promising properties like large thrust, high velocity, and quick response. Then, as applications of electrostatic force, powerful electrostatic motor and new technologies of electrostatic transportation of particles, powder and droplets, sheets and films, and thin plates, are presented respectively with their principles and devices. And combining the technologies of electrostatic suspension without mechanical contact and electrostatic drives, super clean transportation devices for 300 mm and 400 mm silicon wafers and thin plates of glass for flat displays are introduced."Thu, 03 Sep 2015 23:02:28 +0200http://www.mpq.mpg.de/events/7130/5381003?14413141482015-09-03T23:02:28+02:00"Controlling Open Quantum Systems: From Dissipation-Protected to Dissipation-Driven Quantum Engineering."
http://www.mpq.mpg.de/events/7129/5381003
<strong>Speaker</strong>: Prof. Lorenza Viola, Dartmouth College, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.06.2013 11:30<br><strong>Summary</strong>: "Precisely controlling the dynamics of real-world open quantum systems is a central challenge across quantum science and technology, with implications ranging from quantum to condensed-matter physics and fault-tolerant quantum information processing. While overcoming the effect of uncontrolled decoherence and dissipation mechanisms is essential to meet this challenge, engineering the coupling to a dissipative environment can likewise be instrumental to a number of quantum control applications, notably open-system quantum simulators. In this talk, I will describe recent advances in pursuing these two complementary approaches. In particular, I will focus on two representative problems: using dynamical decoupling methods for non-Markovian error suppression to achieve high-fidelity quantum memory for long times, while minimizing access latency and sequencing complexity; and designing Markovian dissipative dynamics to drive a many-qubit system to an entangled steady-state of interest, while respecting physical locality constraints."Thu, 03 Sep 2015 23:02:28 +0200http://www.mpq.mpg.de/events/7129/5381003?14413141482015-09-03T23:02:28+02:00"Modeling and characterizing chiral topological states in two-dimensional lattices".
http://www.mpq.mpg.de/events/7128/5381003
<strong>Speaker</strong>: Dr. Hong-Hao Tu, Max-Planck-Institut für Quantenoptik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.06.2013 11:30<br><strong>Summary</strong>: "Chiral topological states are exotic quantum phases of matter in two dimensions with broken time-reversal symmetry (e.g. fractional quantum Hall states). These states support topological ground state degeneracy, stable gapless edge excitations, and quasiparticles carrying fractional charges and fractional statistics. In this talk, I will discuss the bulk-edge correspondence as a powerful tool for modeling and characterizing chiral topological phases in 2D lattices. In the first part, I will describe how chiral topological wave functions and their parent Hamiltonians can be constructed by using the chiral correlators of the edge conformal field theory. In the second part, I will introduce a new quantity named as momentum polarization, which allows extracting topological spin and chiral central charge from the ground-state wave functions and provides an efficient approach to identify 2D chiral topological states from finite-size numerics."Thu, 03 Sep 2015 23:02:28 +0200http://www.mpq.mpg.de/events/7128/5381003?14413141482015-09-03T23:02:28+02:00"Non-equilibrium quantum dynamics of spin impurities using ultracold atoms."
http://www.mpq.mpg.de/events/7127/5381003
<strong>Speaker</strong>: Dr. Takeshi Fukuhara, Max-Planck-Institut für Quantenoptik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.06.2013 11:30<br><strong>Summary</strong>: "Ultracold-atom experiments are suitable to study out-of-equilibrium dynamics of quantum many-body systems. Here I will present the quantum dynamics of deterministically and locally created mobile spin impurities in the one-dimensional bosonic atoms in optical lattices. First, we investigate the dynamics of a single-spin impurity. In the Mott-insulating regime, the coherent propagation of a magnetic excitation, or a magnon, in the Heisenberg model can be observed. Extending the study to the superfluid regime of the bath, we quantitatively determine how the bath affects the motion of the impurity, showing evidence of polaronic behavior. Second, we observe bound states of two magnons in a Heisenberg chain by tracking their dynamics. Such bound states were pointed out theoretically by H. Bethe in 1931, and our novel microscopic study of quantum magnets can directly confirm their existence."Thu, 03 Sep 2015 23:02:27 +0200http://www.mpq.mpg.de/events/7127/5381003?14413141472015-09-03T23:02:27+02:00"New tools for precision metrology: Spatial Coherent Control and Ramsey Comb Spectroscopy."
http://www.mpq.mpg.de/events/7126/5381003
<strong>Speaker</strong>: Prof. Kjeld Eikema, Vrije Universiteit, Amsterdam<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.05.2013 11:30<br><strong>Summary</strong>: "Direct frequency comb spectroscopy (DFCS) is a powerful application of frequency combs that is increasing in importance rapidly. In my talk I will discuss two new methods related to DFCS that we developed in our pursuit of precision spectroscopy of the ground states of helium and the helium-ion. The first method is spatial coherent control with comb laser pulses, which enables complex pattern formation and background elimination with two-photon DFCS. Secondly, I will discuss Ramsey-comb spectroscopy, which combines high pulse energies at the mJ level with the accuracy and resolution of frequency combs. It is based on a new laser system that can selectively and phase coherently amplify two frequency comb pulses at widely different time delays. The high pulse energy provides straightforward access to multi-photon transitions and nonlinear wavelength conversion, while the original frequency comb laser accuracy and resolution is fully recovered from a series of Ramsey-like measurements. The special properties of this approach, such as a cancelation of optical light-shift effects, are demonstrated by improving the accuracy of several weak two-photon transitions in atomic rubidium and cesium up to thirty times."Thu, 03 Sep 2015 23:02:26 +0200http://www.mpq.mpg.de/events/7126/5381003?14413141462015-09-03T23:02:26+02:00"Superfluid atom circuits".
http://www.mpq.mpg.de/events/7125/5381003
<strong>Speaker</strong>: Prof. Gretchen Campbell, University of Maryland, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 21.05.2013 11:30<br><strong>Summary</strong>: "We have created a superfluid atom circuit using a toroidal Bose-Einstein Condensate. Just as a current in a superconducting circuit will flow forever, if a current is created in our superfluid circuit, the flow will not decay as long as the current is below a critical value. A repulsive optical barrier across one side of the torus creates the tunable weak link in the condensate circuit and can be used to control the current around the loop. By rotating the weak link at low rotation rates, we have observed phase slips between well-defined persistent current states. This behavior is analogous to that of a weak link in a superconducting loop. A feature of our system is the ability to dynamically vary the weak link, which in turn varies the critical current, a feature that is difficult to implement in superconducting circuits. For higher rotation rates, we observe a transition to a regime where vortices penetrate the bulk of the condensate. These results demonstrate an important step toward realizing an atomic SQUID analog."Thu, 03 Sep 2015 23:02:26 +0200http://www.mpq.mpg.de/events/7125/5381003?14413141462015-09-03T23:02:26+02:00"Quantum Theory of the Classical."
http://www.mpq.mpg.de/events/7124/5381003
<strong>Speaker</strong>: Professor Wojciech Zurek, Los Alamos National Laboratory, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.05.2013 11:30<br><strong>Summary</strong>: "I will describe three insights into the transition from quantum to classical. I will start with (i) a minimalist (decoherence-free) derivation of preferred states. Such pointer states define events (e.g., measurement outcomes) without appealing to Born's rule . Probabilities and; (ii) Born’s rule can be then derived from the symmetries of entangled quantum states. Derivation of Born’s rule will be the focus of my presentation. With probabilities at hand one can analyze information flows from the system to the environment in course of decoherence. They explain how (iii) robust “classical reality” arises from the quantum substrate by accounting for objective existence of pointer states of quantum systems through redundancy of their records in the environment. Taken together, and in the right order, these three advances elucidate quantum origins of the classical." *W. H. Zurek, Nature Physics 5, 181-188 (2009)Thu, 03 Sep 2015 23:02:25 +0200http://www.mpq.mpg.de/events/7124/5381003?14413141452015-09-03T23:02:25+02:00"Elementary Particles of Superconductivity."
http://www.mpq.mpg.de/events/7123/5381003
<strong>Speaker</strong>: Prof. Assa Auerbach, Technion, Haifa, Israel<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 30.04.2013 11:30<br><strong>Summary</strong>: "Historically, two paradigms competed to explain superconductivity (i) Bose Einstein Condensation (BEC) of weakly interacting Charge 2e pairs (Schafroth), and (ii) Pairing instability of the Fermi liquid (BCS). BCS theory was the unquestionable winner until the late 80's. BCS approximations however, have suffered major setbacks in the advent of high temperature, short coherence length superconductors, such as cuprates, pnictides, and granular superconducting films. A third paradigm has offered itself for understanding some properties of unconventional superconductors: Strongly Interacting Lattice Bosons (LB). LB behave less like in BEC's or or BCS theory, but (strangely) more like localized quantum spins. Their static correlations are very well understood by theories of quantum antiferromagnets. Their dynamics have only recently been explored. Near commensurate fillings they exhibit the condensed matter version of the Higgs mode. Conductivity of Lattice Bosons exhibit strange metallic properties which may explain phenomenology of unconventional superconductors in their "normal" state. LB also exhibit interesting vortex dynamics and Hall conductivity sign reversals."Thu, 03 Sep 2015 23:02:25 +0200http://www.mpq.mpg.de/events/7123/5381003?14413141452015-09-03T23:02:25+02:00"Ultrafast and Nonlinear X-Ray Scattering in Solids."
http://www.mpq.mpg.de/events/7122/5381003
<strong>Speaker</strong>: Prof. David Reis, Stanford University<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 23.04.2013 11:30<br><strong>Summary</strong>: "There has been remarkable progress on using the combination of short pulse, high spatial coherence and large flux from x-ray free electron lasers (FEL) for nonperiodic imaging and nanocrystallography. The possibility of atomic-scale imaging remains a primary motivation for the construction of FELSs. Their unprecedented properties also motivate the study the dynamics of atomic-scale fluctuations directly in the time-domain. However, an important open question is under what conditions the textbook picture of linear, x-ray–matter interactions holds. In this colloquium, I will describe evidence for coherent nonlinear interactions at LCLS and SACLA FELs as well as the first direct time-domain measurements of the dispersion relation for lattice vibrations in photo-excited materials."Thu, 03 Sep 2015 23:02:25 +0200http://www.mpq.mpg.de/events/7122/5381003?14413141452015-09-03T23:02:25+02:00"Few-cycle intense mid-IR waveforms and novel electron dynamics: Strong field physics and extreme nonlinear optics in the mid-IR."
http://www.mpq.mpg.de/events/7121/5381003
<strong>Speaker</strong>: Prof. Jens Biegert, The Institute of Photonics Sciences (ICFO), Spanien<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 16.04.2013 11:30<br><strong>Summary</strong>: "Liberation of an electron is the first step of the recollision model describing high order harmonic generation and attosecond pulse generation. Orbital tomography and electron self-diffraction imaging furthermore intimately rely on a firm grasp of electron dynamics in the Coulomb field of their parent molecular ion. These strong field effects all rely on tunneling dynamics which we study with true mid-IR waveforms. I will show unexpected electron dynamics, and first 3D momentum measurements, when probed, without the ubiquitous ambiguities at the Ti:Sa range, in the non-perturbative tunneling regime. The availability of intense ultrashort pulses at 3100 nm permits exploitation of nonlinear pulse propagation in the anomalous dispersion regime leading to interesting X-wave dynamics, unprecedentedly large supercontinua and stable pulse self-compression in bulk media."Thu, 03 Sep 2015 23:02:25 +0200http://www.mpq.mpg.de/events/7121/5381003?14413141452015-09-03T23:02:25+02:00"Variational methods in quantum many-body physics."
http://www.mpq.mpg.de/events/7120/5381003
<strong>Speaker</strong>: Professor Frank Verstraete, Universität Wien, Faculty of Phys., Quantum Optics, -Nanophysics and -Information<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 22.01.2013 12:30<br><strong>Summary</strong>: "We will review successes and limitations of the variational method in quantum many-body physics; both the time-independent and the time dependent variational method will be illustrated. Special attention will be paid to the role of entanglement in strongly correlated systems and quantum field theory, to classes of wavefunctions that naturally encompass the required entanglement, and to Ansätze for describing elementary excitations and particles on top of the strongly correlated vacuum."Thu, 03 Sep 2015 23:02:24 +0200http://www.mpq.mpg.de/events/7120/5381003?14413141442015-09-03T23:02:24+02:00"A Centrifuge Decelerator: Slowing down Molecular Beams with an Inertial Force."
http://www.mpq.mpg.de/events/7119/5381003
<strong>Speaker</strong>: Dr. Sotir Chervenkov, Max-Planck-Institut für Quantenoptik, Abt. Quantendynamik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.01.2013 12:30<br><strong>Summary</strong>: "Achieving better control and ability to manipulate molecules by decelerating and cooling them is important for various fields of research, such as, many-body physics, quantum information science, cold chemistry, investigation of the fundamental properties of matter, etc. Towards this end, here we present the concept of and demonstrate the first experimental results from a novel and versatile decelerator for continuous beams of neutral polar molecules, which employs the centrifugal potential in a rotating frame. With this technique, deceleration of continuous supersonic beams from a cryogenic source is conceivable. This is expected to provide large samples of slow and internally cold molecules amenable to further cooling down to quantum degenerate regimes."Thu, 03 Sep 2015 23:02:24 +0200http://www.mpq.mpg.de/events/7119/5381003?14413141442015-09-03T23:02:24+02:00"Strong-field-induced electron dynamics and attosecond phenomena in solids."
http://www.mpq.mpg.de/events/7118/5381003
<strong>Speaker</strong>: Dr. Vladislav Yakovlev, Max-Planck-Institut für Quantenoptik, Abt. Attosekundenphysik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.01.2013 12:30<br><strong>Summary</strong>: "In this talk, I will give an overview of our recent work on studying electron dynamics in dielectrics exposed to few-cycle laser pulses with a peak intensity just below the damage threshold. Until recently, detailed time-resolved measurements of electron dynamics in this extreme regime of light-matter interaction used to be out of reach. The situation has recently changed due to the progress in the generation of few-cycle laser pulses and the related progress in attosecond physics. After a brief presentation of recent experiments performed in the Laboratory for Attosecond Physics (MPQ, Garching), I will report on our related theoretical work, where we studied the dynamics of interband excitations and the light-driven motion of charge carriers under conditions where the conventional nonlinear optics breaks down, and the Bragg-like scattering of electrons at edges of the Brillouin zone (Bloch oscillations) starts to play an important role."Thu, 03 Sep 2015 23:02:24 +0200http://www.mpq.mpg.de/events/7118/5381003?14413141442015-09-03T23:02:24+02:00"A Little Big Bang: Strong Interactions in Ultracold Fermi Gases."
http://www.mpq.mpg.de/events/7117/5381003
<strong>Speaker</strong>: Professor Martin Zwierlein, Massachusetts Institute of Technology, Ultracold Quantum Gases Group<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.01.2013 12:30<br><strong>Summary</strong>: "Fermions, particles with half-integer spin such as electrons, protons and neutrons, are the building blocks of matter. When fermions strongly interact, complex collective behavior emerges, as found for electrons in high-temperature superconductors, for neutrons in neutron stars or for quarks in the primordial matter of the early universe. Ultracold Fermi gases of atoms are a new type of strongly interacting fermionic matter that can be created and studied in the laboratory with exquisite control. Non-equilibrium processes are observable in real time. We can study the collision of "spin up" and "spin down" Fermi gases with resonant, quantum limited interactions. In equilibrium, direct absorption images of the trapped atomic gas reveal the entire thermodynamics of the system, including the transition into the superfluid state. The specific heat of the gas displays a characteristic lambda-like feature at the superfluid critical temperature of 17% of the Fermi temperature. Scaled to the density of electrons, superfluidity would occur far above room temperature. We were recently able to follow the evolution of fermion pairing from three to two dimensions and to engineer spin-orbit coupling in these systems, connecting quite directly to models of layered superconductors and topological states of matter. Our measurements in and out of equilibrium provide benchmarks for current many-body theories and will help to understand other strongly interacting Fermi systems, such as high-temperature superconductors and neutron stars."Thu, 03 Sep 2015 23:02:23 +0200http://www.mpq.mpg.de/events/7117/5381003?14413141432015-09-03T23:02:23+02:00"Entanglement and Sub-SQL Sensing: Quantum Trajectories without Quantum Uncertainty."
http://www.mpq.mpg.de/events/7116/5381003
<strong>Speaker</strong>: Professor Klemens Hammerer, Leibniz Universität Hannover, Theoretical Physics / Macroscopic Quantum Objects<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.12.2012 12:30<br><strong>Summary</strong>: "Recent experimental and theoretical work demonstrated the power of dissipative dynamics for generating coherent quantum effects. In this context I will present theoretical results on position- and force sensing with precision below the standard quantum limit employing stationary entanglement between an optomechanical system - as the detector - and an atomic ensemble - as a catalyst for back action cancellation. I will also mention other applications of dissipative quantum dynamics in cavity QED for quantum simulations and quantum control."Thu, 03 Sep 2015 23:02:23 +0200http://www.mpq.mpg.de/events/7116/5381003?14413141432015-09-03T23:02:23+02:00"Ion Coulomb crystals: an unusual form of condensed matter."
http://www.mpq.mpg.de/events/7115/5381003
<strong>Speaker</strong>: Professor Giovanna Morigi, Universität Saarbrücken, Theoretische Physik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.12.2012 12:30<br><strong>Summary</strong>: "Singly-charged ions in traps can form strings at low temperatures, where ordering is due to the interplay of the confining potential and the Coulomb repulsion. At zero temperature the ion string exhibits a structural phase transition to a zigzag structure, tuned by reducing the transverse trap potential or the interparticle distance [1]. The transition is driven by transverse, short wavelength vibrational modes [2]. This is a quantum phase transition, which can be experimentally realized and probed. Indeed, by means of a mapping to the Ising model in a transverse field, the quantum critical point can be determined in terms of the system parameters, finding a finite, measurable deviation from the critical point predicted by the classical theory. A measurement procedure is suggested which can probe the effects of quantum fluctuations at criticality [3]. We then consider the stability and dynamics of an ion chain confined inside a high-finesse optical resonator. When the dipolar transition of the ions strongly couples to one cavity mode, the mechanical effects of light modify the chain properties close to a structural transition. We focus on the linear chain close to the zigzag instability and show that linear and zigzag arrays are bistable for certain strengths of the laser pumping the cavity. For these regimes the chain is cooled into one of the configurations by cavity-enhanced photon scattering. The excitations of these structures mix photonic and vibrational fluctuations, which can be entangled at steady state. These features are signalled by Fano-like resonances in the spectrum of light at the cavity output [4]." [1] "Multiple-shell structures of laser-cooled 24Mg+ ions in a quadrupole storage ring" G. Birkl, S. Kassner, and H. Walther, Nature (London) 357, 310 (1992). [2] "Structural phase transitions in low-dimensional ion crystals", Sh. Fishman, G. De Chiara, T. Calarco, and G. Morigi, Phys. Rev. B 77, 064111 (2008). [3] "Quantum zigzag transition in ion chains", E. Shimshoni, G. Morigi, S. Fishman, Phys. Rev. Lett 106, 010401 (2011). [4] "Structural Transitions of Ion Strings in Quantum Potentials", Cecilia Cormick and Giovanna Morigi, Phys. Rev. Lett. 109, 053003 (2012).Thu, 03 Sep 2015 23:02:23 +0200http://www.mpq.mpg.de/events/7115/5381003?14413141432015-09-03T23:02:23+02:00"Attosecond–resolved quantum dynamics: Opportunities and challenges."
http://www.mpq.mpg.de/events/7114/5381003
<strong>Speaker</strong>: Professor Joachim Burgdörfer, Technische Universität Wien, Theoretische Physik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 04.12.2012 12:30<br><strong>Summary</strong>: "With the advent of sub-femtosecond ultrashort XUV pulses and of phase-stabilized IR pulses with sub-cycle time resolution, novel pathways have been opened up for studying time-resolved electronic quantum dynamics on the attosecond scale. These experiments pose challenges for theory: How do short pulses interact with matter? Which novel information can be extracted from time-resolved spectroscopies? In this talk, these issues will be addressed with the help of a few examples. One is the notion of time delay as physical observable. We show that the Eisenbud-Wigner-Smith time delay for atomic photoionization can now be determined by streaking or RABBITT with single-digit attosecond precision, however only when long-range interaction and IR field corrections are accounted for. For the more complex systems of a solid surface, time-resolved information on decohering processes such as electron transport or plasmon excitation can be extracted."Thu, 03 Sep 2015 23:02:23 +0200http://www.mpq.mpg.de/events/7114/5381003?14413141432015-09-03T23:02:23+02:00"Strong effective magnetic fields and Zak-Berry phases in optical lattices."
http://www.mpq.mpg.de/events/7113/5381003
<strong>Speaker</strong>: Marcos Atala, Max Planck Institut für Quantenoptik, Abt. Quanten-Vielteilchensysteme<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 27.11.2012 12:30<br><strong>Summary</strong>: "Geometric phases are manifested in many phenomena, like quantum Hall effect, and can characterize the topological properties of Bloch bands. For example in one-dimensional periodic potentials the topological invariant is given by the Zak phase-- the Berry phase acquired during an adiabatic motion of a particle across the Brillouin zone.In this talk I will present two topics, the first one will be about the experimental realization of strong effective magnetic fields in a two-dimensional optical lattice. By use of Raman-assisted atom tunneling we imprint a geometric phase to the atoms which can be interpreted as an Aharonov-Bohm phase. We observe that the effective magnetic field leads to a frustrated ground state and to quantum cyclotron orbits.The second topic will be about the direct measurement of the Zak phase for a dimerized optical lattice, which models polyacetylene. The experimental protocol consists of a combination of Bloch oscillations and Ramsey interferometry. This work establishes a new general approach for probing the topological structure of Bloch bands in optical lattices."Thu, 03 Sep 2015 23:02:22 +0200http://www.mpq.mpg.de/events/7113/5381003?14413141422015-09-03T23:02:22+02:00"An optical lattice based quantum simulator for relativistic fermions and topological insulators."
http://www.mpq.mpg.de/events/7112/5381003
<strong>Speaker</strong>: Dr. Matteo Rizzi, Max Planck Institut für Quantenoptik, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 27.11.2012 12:30<br><strong>Summary</strong>: "We present a proposal for a versatile cold-atom-based quantum simulator of relativistic fermionic theories and topological insulators in arbitrary dimensions [1]. The setup consists of a spin-independent optical lattice that traps a collection of hyperfine states of the same alkaline atom, to which the different degrees of freedom of the field theory to be simulated are then mapped. We show that the combination of bi-chromatic optical lattices with Raman transitions can allow the engineering of a spin-dependent tunneling of the atoms between neighboring lattice sites. These assisted-hopping processes can be employed for the quantum simulation of various interesting models, including the realization of different types of relativistic lattice fermions, which can then be exploited to synthesize a majority of phases in the periodic table of topological insulators. An example concerns how to implement Wilson fermions with inverted masses: the atomic gas corresponds to a phase of matter where Maxwell electrodynamics is replaced by axion electrodynamics, i.e. a 3D topological insulator [2]."Thu, 03 Sep 2015 23:02:22 +0200http://www.mpq.mpg.de/events/7112/5381003?14413141422015-09-03T23:02:22+02:00"Superconducting Quantum Circuits: Ultra-strong Light-Matter Interaction and Path Entanglement of Continuous-variable Quantum Microwaves."
http://www.mpq.mpg.de/events/7111/5381003
<strong>Speaker</strong>: Professor Rudolf Gross, Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, TUM<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.11.2012 12:30<br><strong>Summary</strong>: "Superconducting nanocircuits behave in many aspects similar to natural atoms. Despite the fact that these so-called artificial atoms are huge compared to their natural counterparts, they have a discrete level structure and exhibit properties unique to the world of quantum mechanics. In the simplest case, these artificial atoms form quantum two-level systems, also called quantum bits. We have realized superconducting flux quantum bits where the quantum two-level system is formed by symmetric and anti-symmetric superposition states of persistent currents circulat-ing clock- and anticlockwise in a superconducting loop [1]. Coupling these flux qubits to on-chip superconducting microwave resonators gives rise to the prospering field of superconducting circuit quantum electrodynamics (circuit-QED), which allows us to study the fundamental inter-action between artificial solid-state atoms and single microwave photons as the basis for com-municating quantum information. We discuss the realization of circuit-QED systems operating in the ultra-strong coupling regime, where the atom-cavity coupling rate reaches a considerable fraction of the atom transition frequency [2]. We also address quantum state tomography of propagating microwaves using a novel dual path detection scheme [3]. We have used this scheme to demonstrate for the first time frequency degenerate path entanglement of continu-ous-variable propagating quantum microwave signals. To this end, we entangle two spatially separate modes of the same frequency using a hybrid ring beam splitter and detect the entan-glement by means of cross-correlation techniques. The input fields of the beam splitter are squeezed vacuum and vacuum, respectively, and the correlations are evaluated up to the fourth moments in amplitude.This work is supported by the German Research Foundation via SFB 631 and the German Excellence Initia-tive via the Nanosystems Initiative Munich (NIM)."[1] T. Niemczyk et al., Supercond. Sci. Techn. 22, 034009 (2009); F. Deppe et al., PRB 76, 214503 (2007).[2] T. Niemczyk et al., Nat. Phys. 6, 772-776 (2010); F. Deppe et al., Nat. Phys. 4, 686 (2008); T. Niemczyk et al., arXiv:1107.0810v1.[3] E. Menzel et al., Phys. Rev. Lett. 105, 100401 (2010); M. Mariantoni et al., Phys. Rev. Lett. 105, 133601 (2010).Thu, 03 Sep 2015 23:02:22 +0200http://www.mpq.mpg.de/events/7111/5381003?14413141422015-09-03T23:02:22+02:00"Table-top ultrafast X-ray science at ALLS."
http://www.mpq.mpg.de/events/7110/5381003
<strong>Speaker</strong>: Professor François Légaré, Institut National de la Recherche Scientifique (INRS), Canada<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.11.2012 14:00Thu, 03 Sep 2015 23:02:22 +0200http://www.mpq.mpg.de/events/7110/5381003?14413141422015-09-03T23:02:22+02:00"Cavity QED with fiber Fabry-Perot cavities."
http://www.mpq.mpg.de/events/7109/5381003
<strong>Speaker</strong>: Professor Jakob Reichel, Laboratoire Kastler Brossel, Paris<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.11.2012 12:30<br><strong>Summary</strong>: "Miniature, fiber-based Fabry-Perot cavities (FFPs) are enabling novel experiments in cavity quantum electrodynamics, with cold atoms as well as with solid-state emitters. We have used such an FFP cavity to create an entangled state in a small ensemble of about 20 atoms, extracted from a BEC on an atom chip. We also use the cavity to measure the Husimi distribution of this entangled multi-atom state. In will also describe a new experiment where an FFP cavity is used to prepare a Bose-Einstein condensate of exciton polaritons in a semiconductor quantum well. Thu, 03 Sep 2015 23:02:21 +0200http://www.mpq.mpg.de/events/7109/5381003?14413141412015-09-03T23:02:21+02:00"Beyond Standard Optical Lattices: Topological Insulators and Frustrated Magnetism."
http://www.mpq.mpg.de/events/7108/5381003
<strong>Speaker</strong>: Professor Walter Hofstetter, Goethe-Universität Frankfurt am Main, Quantum Matter Theory Group<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 30.10.2012 12:30<br><strong>Summary</strong>: "The last years have witnessed dramatic progress in experimental control and refinement of optical potentials for ultracold atoms. Two major recent developments are the realization of synthetic gauge fields for neutral atoms,allowing the simulation of topologically nontrivial phases of matter, and the creation of frustrated lattice geometries such as triangular or Kagome. Particularly rich physics arises in the presence of multiple atomic species and strong interactions, which I will discuss for two different examples. 1) We consider a spinful and time-reversal invariant version of the Hofstadter problem which can be realized in ultracold atoms. In these experiments, an additional staggered potential and spin-orbit coupling are available. Without interactions, the system exhibits various phases such as topological and normal insulator, metal as well as semi-metal phases with two or even more Dirac cones. Using a combination of real-space dynamical mean-field theory and analytical techniques, we discuss the effect of on-site interactions and determine the corresponding phase diagram. In particular, we investigate the stability of topological insulator phases in the presence of strong interactions. We compute spectral functions which allow us to study the edge states of strongly correlated topological phases. 2) We study Bose-Bose mixtures on a triangular lattice, in the case of total filling one where geometric frustration arises for asymmetric hopping. We map out a rich ground state phase diagram including xy-ferromagnetic, spin-density wave, superfluid, and supersolid phases. In particular, we identify a stripe spin-density wave phase for highly asymmetric hopping. On top of the spin-density wave, we find that the system generically shows weak charge (particle) density wave order."Thu, 03 Sep 2015 23:02:21 +0200http://www.mpq.mpg.de/events/7108/5381003?14413141412015-09-03T23:02:21+02:00"Rydberg blockade, slow light and interacting dark-state polaritons."*
http://www.mpq.mpg.de/events/7107/5381003
<strong>Speaker</strong>: Professor Matthias Weidemüller, Universität Heidelberg, Physics Institute and Center for Quantum Dynamics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 23.10.2012 11:30<br><strong>Summary</strong>: "Interfacing light and matter at the quantum level is at the heart of modern atomic and optical physics and is a unifying theme of many diverse areas of research. A prototypical realization is electromagnetically induced transparency (EIT), whereby quantum interference gives rise to long-lived hybrid states of atoms and photons called dark-state polaritons. In my talk I will give a general introduction into the field of ultracold Rydberg gases, with special emphasis on recent developments towards nonlinear quantum optics and the observation of strong interactions between dark-state polaritons in an ultracold atomic gas involving highly excited (Rydberg) states. By combining optical imaging with counting of individual Rydberg excitations we probe both aspects of this atom-light system. Extreme Rydberg-Rydberg interactions give rise to a polariton blockade, which is revealed by a strongly nonlinear optical response of the atomic gas. For our system the polaritons are almost entirely matter-like allowing us to directly measure the statistical distribution of polaritons in the gas. For increasing densities we observe a clear transition from Poissonian to sub-Poissonian statistics, indicating the emergence of spatial and temporal correlations between polaritons. These experiments, which can be thought of as Rydberg dressing of photons, show that it is possible to control the statistics of light fields, and could form the basis for new types of long-range interacting quantum fluids." * Work performed in collaboration with Christoph Hofmann, Georg Günter, Hanna Schempp, Martin Robert-de-Saint-Vincent and Shannon Whitlock Thu, 03 Sep 2015 23:02:21 +0200http://www.mpq.mpg.de/events/7107/5381003?14413141412015-09-03T23:02:21+02:00"Quantum properties of polariton fluids in semiconductor microcavities."
http://www.mpq.mpg.de/events/7106/5381003
<strong>Speaker</strong>: Professor Elisabeth Giacobino, Laboratoire Kastler Brossel, Ecole Normale Supérieure, Université Pierre et Marie Curie, CNRS<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 16.10.2012 11:30<br><strong>Summary</strong>: "Polaritons are very special quasi-particles, which are a mixture of matter and light. In a semiconductor microcavity exciton-polaritons arise from strong coupling between cavity photons and quantum well excitons (bound electron-hole states). What makes them very attractive is the possibility of combining the coherent properties of photons with the highly interacting features of electronic states. They have recently demonstrated unprecedented non-linearities, Bose-Einstein condensation and superfluidity.First, I will show that these nonlinearities can bring quantum optical effects, as well as polarization controlled optical gates, spin control and ultra-fast spin switching. In addition, due to their very low mass (~10-4 times that of the electron, inherited from their photonic component), polaritons also exhibit condensation and quantum fluid properties at temperatures of a few K. I will present our recent results, demonstrating superfluid motion of polaritons, which manifests itself as the ability to flow without friction when the flow velocity is slower than the speed of sound in the fluid. Cerenkov-like wake patterns, vortices and dark solitons are also observed when the flow velocity is varied."Thu, 03 Sep 2015 23:02:20 +0200http://www.mpq.mpg.de/events/7106/5381003?14413141402015-09-03T23:02:20+02:00“A toolbox for delocalization experiments with atoms, molecules and clusters of atoms and molecules.”
http://www.mpq.mpg.de/events/7104/5381003
<strong>Speaker</strong>: Prof. Dr. Markus Arndt, Universität Wien; Quantum nanophysics & Molecular quantum optics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.07.2012 11:30<br><strong>Summary</strong>: "Recent experiments in Vienna have shown that large covalently bound complexes, composed of several hundred atoms, can be delocalized over hundred times their own size and maintain quantum coherence over many milliseconds , even when heated to several hundred Kelvin. Two major motivations are driving this research: Nanoparticle interferometry turns out to be optimized for testing new measures of quantum macroscopicity. We will discuss the molecular beam methods and coherent manipulation schemes that are required to push the current state-of-the-art by the next orders of magnitude where new bounds will be set to non-standard quantum models at the quantum-classical interface. Molecular interferograms are quantum nanorulers either in position space or in the time-domain They have an intrinsic force sensitivity down to the Yoctonewton level and are therefore well-suited for novel measurements of magnetic, structural, electronic and optical properties of molecules, clusters and other nanoparticles with widely delocalized quantum states in controlled external fields."1. K. Hornberger et al., Rev. Mod. Phys. 84, 157 (2012).2. S. Nimmrichter et al., Phys. Rev. A 83, 043621 (2011).3. S. Gerlich et al., Nature Communs. 2, 263 (2011).4. T. Juffmann et al., Phys. Rev. Lett. 103, 263601 (2009).5. S. Gerlich et al. Angew. Chem. Int. Ed. 47, 6195 (2008).6. S. Gerlich et al., Nature Phys. 3, 711 (2007).7. L. Hackermüller, NATURE 427, 711-714 (2004).Thu, 03 Sep 2015 23:02:19 +0200http://www.mpq.mpg.de/events/7104/5381003?14413141392015-09-03T23:02:19+02:00The shadow of a single atom
http://www.mpq.mpg.de/events/7105/5381003
<strong>Speaker</strong>: Prof. David Kielpinski, Griffith University, Brisbane, Australia<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.07.2012 08:00<br><strong>Summary</strong>: We have performed absorption imaging of a single atom for the first time [1]. A trapped Yb+ atomic ion scatters light out of an illumination beam tuned to atomic resonance at 369.5 nm. When the beam is reimaged onto a CCD camera, we observe an absorption image of 440 nm diameter and 5% contrast. The absorption contrast is investigated as a function of laser intensity and detuning, and closely conforms to the limits imposed by simple quantum theory and known properties of our imaging system. Defocused absorption images provide spatial interferograms of the scattered light, permitting accurate retrieval of the amplitude and phase of the scattered wave. We measure a phase shift of >1 radian in the scattered light as a function of laser detuning, which may be useful in quantum information protocols. The interferograms point to the possibility of observing the focusing of light by a single atom.[1] Streed et al., accepted to Nature Commun Thu, 03 Sep 2015 23:02:19 +0200http://www.mpq.mpg.de/events/7105/5381003?14413141392015-09-03T23:02:19+02:00“Phase-resolved THz spectroscopy.”
http://www.mpq.mpg.de/events/7103/5381003
<strong>Speaker</strong>: Prof. Dr. Karl Unterrainer, TU Wien, Photonik Institut u. Zentrum für Mikro- & Nanostrukturen<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.07.2012 11:30<br><strong>Summary</strong>: "The generation of coherent THz pulses from femto-second sources has enormously progressed during the last 10 years. The band-width, intensities, as well as the efficiency has increased by using advanced semiconductor emitters and non-linear processes. In this way the spectral range up to 100 THz can be covered by quasi single cycle THz pulses. This frequency range – previously inaccessible for time-resolved spectroscopy - is an important part of the electro-magnetic spectrum due to a large number of fundamental resonances. Vibrational and rotational resonances of molecules are attractive for chemical sensing (chemical fingerprint analysis) and spectroscopic imaging. In solids, the resonance energies of phonons, plasmons and impurity transition are within the THz range. In particular also the transition energies of semiconductor nano structures occur in the THz band.Time-resolved THz spectroscopy allows phase-locked measurements – in particular phase-resolved detection. We take advantage of this fine capability to study the dynamics of semiconductor nanostructures. Phase-resolved THz spectroscopy allows unique measurements of stimulated emission form Quantum-Cascade Lasers. The knowledge of the phase of the THz response provides fascinating insights into the quantum mechanical processes. The study of highly excited nanostructures allows the prediction for coherent control schemes for optoelectronic devices. Together with novel resonator concepts we are able to show THz “switching” and strong coupling to quantized transitions."Thu, 03 Sep 2015 23:02:18 +0200http://www.mpq.mpg.de/events/7103/5381003?14413141382015-09-03T23:02:18+02:00"Otto Stern: the nearly forgotten pioneer of atomic, molecular, and nuclear physics."
http://www.mpq.mpg.de/events/7102/5381003
<strong>Speaker</strong>: Prof. Dr. Horst Schmidt-Böcking, Goethe- Universität Frankfurt; Experimental Atomic Physics Group<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.07.2012 11:30<br><strong>Summary</strong>: "Otto Stern is one of the great pioneers of modern atomic, molecular and nuclear physics. In 1943 he received the Nobel prize in physics for his development of the “Molecular Beam Method” and his “Measurement of the Magnetic Moment of the Proton”. The molecular beam method allowed physicists and chemists for the first time to perform experiments on single isolated atoms or molecules and determine inner properties of atoms and nuclei. For the exploration of the quantum world his invention has an importance similar to Gutenberg’s invention of single separated letters for printing of books. Stern was 81 times nominated for the Nobel prize in physics more than Planck, Einstein or any other of the great pioneers. Based on Sterns invention the Maser, the Atomic clock, the nuclear magnetic resonance etc. were developed. In 1933 Stern was forced to emigrate to the US since he was Jewish."Thu, 03 Sep 2015 23:02:18 +0200http://www.mpq.mpg.de/events/7102/5381003?14413141382015-09-03T23:02:18+02:00"High repetition rate frequency combs: ultrafast optics starting with continuous-wave lasers."
http://www.mpq.mpg.de/events/7101/5381003
<strong>Speaker</strong>: Prof. Dr. Andrew M. Weiner, Purdue University, USA; Ultrafast Optics and Opt. Fiber Communication Laboratory<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 06.07.2012 11:30<br><strong>Summary</strong>: "The introduction of mode-locked laser optical frequency combs during the last decade led to revolutionary progress in precision optical frequency synthesis and metrology. Such combs typically operate at repetition rates of hundreds of MHz. Combs at higher repetition rates are of interest for other applications, such as arbitrary waveform generation and radio-frequency signal processing, which do not require full stabilization of the offset frequency. In this talk I discuss two flavors of high repetition rate comb generation starting with a single continuous-wave laser. Continuous-wave lasers subject to strong periodic electro-optic modulation can be formed into optical frequency combs and compressed into trains of picosecond pulses at rates on the order of 10 GHz. Nonlinear optical propagation can extend comb bandwidths into the THz regime, allowing realization of pulse durations at the few hundred femtosecond level, and producing combs with extremely flat and smooth optical power spectra. We have exploited such combs for applications such as line-by-line optical pulse shaping, also known as optical arbitrary waveform generation, and programmable radio-frequency filtering. Generation of combs at much higher repetition rates can be achieved via nonlinear wave mixing in high quality factor (high Q) microresonators. Our group has investigated line-by-line pulse shaping of such combs generated in silicon nitride ring resonators. Our experiments reveal formation of two different types of combs which exhibit strikingly different time domain behaviors. One type can be compressed to nearly bandwidth-limited pulses, which indicates high coherence across the spectrum. A second type exhibits limited compressibility and degraded coherence. Accordingly, understanding and control of the coherence constitutes a topic of significant interest in the further development of microresonator comb generators."Thu, 03 Sep 2015 23:02:18 +0200http://www.mpq.mpg.de/events/7101/5381003?14413141382015-09-03T23:02:18+02:00Quantum simulation of dynamical gauge fields
http://www.mpq.mpg.de/events/7100/5381003
<strong>Speaker</strong>: Prof. Dr. Peter Zoller, Universität Innsbruck; Institute for Theoretical Physics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.07.2012 11:30<br><strong>Summary</strong>: Recently, the condensed matter and atomic physics communities have mutually benefited from synergies emerging from the quantum simulation of strongly correlated systems using atomic setups. While there is presently significant interest in artificial gauge fields mimicking magnetic fields in (neutral) atom setups to observe phenomena like fractional quantum Hall physics, we will discuss prospects of realizing simple models of dynamical gauge fields (lattice gauge theories) as a next generation of possible cold atom experiments. Thu, 03 Sep 2015 23:02:18 +0200http://www.mpq.mpg.de/events/7100/5381003?14413141382015-09-03T23:02:18+02:00Extreme Optics in Semiconductors: When Quasiparticles Collide, and 1+1=11
http://www.mpq.mpg.de/events/7099/5381003
<strong>Speaker</strong>: Prof. Mark S. Sherwin, University of California at Santa Barbara, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.06.2012 13:30<br><strong>Summary</strong>: Intense laser fields can rip electrons from an atom and slam them back into it. By using intense terahertz radiation from UC Santa Barbara’s Free-Electron Lasers, we have observed an analogous phenomenon for photo-excited electrons and holes in a semiconductor. A trillion energetic electron-hole collisions per second convert a monochromatic near-infrared laser beam at 350 THz (0.8 µm) into a polychromatic near-infrared beam containing up to 11 new frequencies spaced by 1 Terahertz. Implications for the nature of optical excitations in solids and possible applications to optical communications will be discussed. Thu, 03 Sep 2015 23:02:17 +0200http://www.mpq.mpg.de/events/7099/5381003?14413141372015-09-03T23:02:17+02:00Quantum interference of single photons from two remote Nitrogen-Vacancy centers in diamond
http://www.mpq.mpg.de/events/7098/5381003
<strong>Speaker</strong>: Dr. Alexander Kubanek, Harvard University, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.06.2012 09:00<br><strong>Summary</strong>: The interference of two identical photons impinging on a beam splitter leads to perfect photon coalescence where both photons leave through the same output port. This fundamental effect, known as Hong-Ou-Mandel (HOM) interference [1], can be used to characterize the properties of quantum emitters with high accuracy. This is a particularly useful tool for quantum emitters embedded in a solid state matrix because their internal properties, unlike those of atoms in free space, can vary substantially from emitter to emitter due to interactions with the environment. Here, we demonstrate HOM interference of photons emitted from two single Nitrogen-Vacancy (NV) centers in diamond that are spatially separated by 2 meters. The frequencies of the photons are controlled by tuning individual optical transitions of associated NVs via a DC electric field. The indistinguishability of the photons paves the way for entanglement generation between remote solid state qubits. [1] C. K. Hong, Z.Y. Ou, and L. Mandel, Phys. Rev. Lett. 59, 2044 (1987).Thu, 03 Sep 2015 23:02:17 +0200http://www.mpq.mpg.de/events/7098/5381003?14413141372015-09-03T23:02:17+02:00Astrophysical evidences for the variation of fundamental constants and proposals of laboratory tests
http://www.mpq.mpg.de/events/7097/5381003
<strong>Speaker</strong>: Prof. Dr. Victor V. Flambaum, University of New South Wales, Canada; Theoretical Physics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 28.06.2012 07:30<br><strong>Summary</strong>: I present a review of recent results on a search for space-time variation of the fundamental constants. New results for the variation of the fine structure constant alpha, based on the quasar absorption spectra data, indicate the variation of alpha in space. The spatial variation can explain fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. There is an agreement between the results obtained using different telescopes and different redshifts. Also, now there are no contradictions between the results obtained by different groups. These astrophysical results may be used to predict the variation effects for atomic clocks. The effects (which appear due to Sun and Earth motions) are very small and require improvement of the clock accuracy by 1-2 orders of magnitude. The improvement of the clock sensitivity may be achieved using 229Th nuclear clocks where expected accuracy of the frequency measurement is 10-19 and the effect of the variation is enhanced by 4-5 orders of magnitude. A comparable accuracy of the frequency measurements may be also achieved in highly charged ions where the effects of the variation are enhanced by an order of magnitude. We found a number of allowed E1 and narrow higher multipolarity clock transitions in such ions. The frequencies are in the laser range due to the configuration crossing phenomenon. There are also enhanced effects in some atomic and molecular transitions. Atomic clocks can also be used to measure possible dependence of the fundamental constants on environment (e.g. density of matter) and gravity.Thu, 03 Sep 2015 23:02:17 +0200http://www.mpq.mpg.de/events/7097/5381003?14413141372015-09-03T23:02:17+02:00"Optical flux lattices for ultracold atomic gases."
http://www.mpq.mpg.de/events/7096/5381003
<strong>Speaker</strong>: Prof. Dr. Nigel Cooper, Cambridge University, Cavendish Laboratory, Theory of Condensed Matter<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 26.06.2012 11:30<br><strong>Summary</strong>: "One of the most important techniques in the ultracold atom toolbox is the optical lattice: a periodic scalar potential formed from standing waves of light. Optical lattices are central to the use of atomic gases as quantum simulators, and allow the exploration of strong-correlation phenomena related to condensed matter systems. In this talk, I shall describe how simple laser configurations can give rise to a new kind of optical lattice -- a so-called "optical flux lattice" -- in which optically dressed atoms experience a periodic effective magnetic flux with high mean density. Optical flux lattices have narrow energy bands with nonzero Chern numbers, analogous to the Landau levels of a charged particle in a uniform magnetic field. These lattices will greatly facilitate the achievement of the quantum Hall regime for ultracold atomic gases."Thu, 03 Sep 2015 23:02:16 +0200http://www.mpq.mpg.de/events/7096/5381003?14413141362015-09-03T23:02:16+02:00"Ultracold ensembles of molecules near quantum degeneracy."
http://www.mpq.mpg.de/events/7095/5381003
<strong>Speaker</strong>: Prof. Dr. Hanns-Christoph Nägerl, Universität Innsbruck; Institute for Experimental Physics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 19.06.2012 11:30<br><strong>Summary</strong>: "Dipolar quantum gas systems at ultralow temperatures are expected to exhibit novel many-body quantum phases as a result of the long-range and anisotropic dipole-dipole interaction. For our Rb-Cs mixture experiment the focus is on the creation of a bosonic quantum gas of polar ground-state RbCs molecules using Feshbach association and subsequent stimulated adiabatic Raman transfer (STIRAP). We have created a high phase-space density sample of ultracold RbCs Feshbach molecules from an ultracold mixture of Rb and Cs and have performed high-resolution molecular spectroscopy using the Feshbach molecules and have found intermediate electronically excited levels suitable for RbCs ground-state transfer. We have measured the binding energy of the RbCs rovibrational ground state in two-photon spectroscopy and have performed STIRAP experiments with transfer efficiencies of up to 90%. We have implemented an optical lattice with the ultimate aim to create a Mott-insulator state having precisely one atom of each species at each lattice site to improve the creation efficiency for the Feshbach molecules and the STIRAP transfer efficiency. Presently, we switch on the lattice after Feshbach molecule creation to localize the molecules and to prevent collisions. To improve the STIRAP efficiency we have set up ultra-stable optical resonators to which we lock the transfer lasers to reduce laser phase noise. Finally, we will give an update on our endeavor to create a BEC of ground-state Cs dimers."Thu, 03 Sep 2015 23:02:16 +0200http://www.mpq.mpg.de/events/7095/5381003?14413141362015-09-03T23:02:16+02:00Cloaking magnetic fields
http://www.mpq.mpg.de/events/7094/5381003
<strong>Speaker</strong>: Prof. Alvar Sanchez, Department of Physics, UAB, Barcelona<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.06.2012 09:30<br><strong>Summary</strong>: Recent advances like transformation optics have opened new possibilities of controlling electromagnetic fields, including cloaking devices that may render an object invisible to incident electromagnetic radiation. These cloaks have been theoretically presented but their practical implementation in microwaves, infrared or even visible light are actually not exact cloaks but only reduced versions (e. g. with only reduced scattering and some shadow). Here we present how in the case of static magnetic fields one can design an exact cloak using simply a superconductor-ferromagnetic bilayer, which makes it a unique case of an exact and feasible cloak. An experimental realization of the magnetic cloak is presented. Thu, 03 Sep 2015 23:02:15 +0200http://www.mpq.mpg.de/events/7094/5381003?14413141352015-09-03T23:02:15+02:00"Superconducting Quantum Circuits: Ultra-strong Light-Matter Interaction and Path Entanglement of Continuous-variable Quantum Microwaves”
http://www.mpq.mpg.de/events/7093/5381003
<strong>Speaker</strong>: Prof. Dr. Rudolf Gross, Walther-Meißner-Institute for Low Temperature Research and Technical University Munich<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 12.06.2012 11:30<br><strong>Summary</strong>: "Superconducting nanocircuits behave in many aspects similar to natural atoms. Despite the fact that these so-called artificial atoms are huge compared to their natural counterparts, they have a discrete level structure and exhibit properties unique to the world of quantum mechanics. In the simplest case, these artificial atoms form quantum two-level systems, also called quantum bits. We have realized superconducting flux quantum bits where the quantum two-level system is formed by symmetric and anti-symmetric superposition states of persistent currents circulat-ing clock- and anticlockwise in a superconducting loop [1]. Coupling these flux qubits to on-chip superconducting microwave resonators gives rise to the prospering field of superconducting circuit quantum electrodynamics (circuit-QED), which allows us to study the fundamental inter-action between artificial solid-state atoms and single microwave photons as the basis for com-municating quantum information. We discuss the realization of circuit-QED systems operating in the ultra-strong coupling regime, where the atom-cavity coupling rate reaches a considerable fraction of the atom transition frequency [2]. We also address quantum state tomography of propagating microwaves using a novel dual path detection scheme [3]. We have used this scheme to demonstrate for the first time frequency degenerate path entanglement of continu-ous-variable propagating quantum microwave signals. To this end, we entangle two spatially separate modes of the same frequency using a hybrid ring beam splitter and detect the entan-glement by means of cross-correlation techniques. The input fields of the beam splitter are squeezed vacuum and vacuum, respectively, and the correlations are evaluated up to the fourth moments in amplitude."This work is supported by the German Research Foundation via SFB 631 and the German Excellence Initia-tive via the Nanosystems Initiative Munich (NIM).[1] T. Niemczyk et al., Supercond. Sci. Techn. 22, 034009 (2009); F. Deppe et al., PRB 76, 214503 (2007).[2] T. Niemczyk et al., Nat. Phys. 6, 772-776 (2010); F. Deppe et al., Nat. Phys. 4, 686 (2008); T. Niemczyk et al., arXiv:1107.0810v1.[3] E. Menzel et al., Phys. Rev. Lett. 105, 100401 (2010); M. Mariantoni et al., Phys. Rev. Lett. 105, 133601 (2010).Thu, 03 Sep 2015 23:02:15 +0200http://www.mpq.mpg.de/events/7093/5381003?14413141352015-09-03T23:02:15+02:00"The complexity of learning quantum states (with applications to face recognition)."
http://www.mpq.mpg.de/events/7092/5381003
<strong>Speaker</strong>: Prof. Dr. David Gross, Universität Freiburg; Quantum Correlations in Physics, Math, and Computer Science<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 05.06.2012 11:30<br><strong>Summary</strong>: "The complete characterization of a quantum system by physical measurements seems to be a conceptually simple task and is routinely carried out experimentally. It is thus all the more surprising that many fundamental questions pertaining to this procedure remain unanswered. (And, what is more, lead to highly non-trivial mathematical problems). A prime example is determining the sample complexity of quantum state estimation: under realistic conditions, how many experimental runs does one need in order to obtain an estimate for an unknown quantum state with acceptable error bars? Simple answers based on asymptotic statistics turn out to be highly inaccurate (in fact, way too pessimistic). I will report recent progress on this and related problems. It is both based on, and has contributed to, new developments in classical statistics and machine learning theory. I will mention proposals for tasks as varied as face recognition and prediction of online behavior which have been influenced by methods from quantum state tomography."Thu, 03 Sep 2015 23:02:14 +0200http://www.mpq.mpg.de/events/7092/5381003?14413141342015-09-03T23:02:14+02:00"An elementary quantum network of single atoms in optical cavities."
http://www.mpq.mpg.de/events/7091/5381003
<strong>Speaker</strong>: Christian Nöllecke, Max-Planck-Institut für Quantenoptik, Abt. Quantendynamik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.05.2012 11:30<br><strong>Summary</strong>: "Quantum networks form the basis of distributed quantum computing architectures and quantum communication. Single atoms in optical cavities are ideally suited as universal quantum network nodes capable of sending, storing and retrieving quantum information. We demonstrate this by presenting an elementary version of a quantum network based on two identical nodes in remote, independent laboratories. The dynamic control of coherent dark states allows for the reversible exchange of quantum information by exchange of a single photon."Thu, 03 Sep 2015 23:02:13 +0200http://www.mpq.mpg.de/events/7091/5381003?14413141332015-09-03T23:02:13+02:00"A quantum information approach to statistical mechanics."
http://www.mpq.mpg.de/events/7090/5381003
<strong>Speaker</strong>: Dr. Gemma De las Cuevas, Max-Planck-Institut für Quantenoptik, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.05.2012 11:30<br><strong>Summary</strong>: "I will show how one can apply quantum information tools to study various problems in statistical mechanics. We focus on classical spin models, which are toy models used in a variety of fields such as magnetism or quantum gravity, and we tackle them from three different angles. First, we show how the partition function of a class of widely different classical spin models (models in different dimensions, different types of many-body interactions, different symmetries, etc) can be mapped to the partition function a single model. Second, we give efficient quantum algorithms to estimate the partition function of various classical spin models, such as the Ising or Potts model. Finally, we outline the possibility of applying quantum information tools to a model of discrete quantum gravity called causal dynamical triangulation."Thu, 03 Sep 2015 23:02:13 +0200http://www.mpq.mpg.de/events/7090/5381003?14413141332015-09-03T23:02:13+02:00"Localization of ultra-cold bosons in a 3D laser speckle disordered potential."
http://www.mpq.mpg.de/events/7089/5381003
<strong>Speaker</strong>: Prof. Dr. Alain Aspect, Laboratoire Charles Fabry, Institut d'Optique, Palaiseau<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 22.05.2012 11:30<br><strong>Summary</strong>: "We have observed 3D localization of ultra-cold atoms of a Bose Einstein Condensate, suspended against gravity, and released in a 3D optical disordered potential with short correlation lengths in all directions. Fluorescence imaging of the expanding cloud yields density profiles composed of a steady localized part and a diffusive part. A phenomenological analysis of the data allows us to determine the localized fraction and the diffusion coefficients of the diffusing part. I will present and discuss these results, in the context of Anderson localization."Thu, 03 Sep 2015 23:02:13 +0200http://www.mpq.mpg.de/events/7089/5381003?14413141332015-09-03T23:02:13+02:00"Spinning electrons with intense circularly polarized pulses to generate circular attosecond pulses - a new tool for electron control."
http://www.mpq.mpg.de/events/7088/5381003
<strong>Speaker</strong>: Prof. Dr. André Dieter Bandrauk, Université de Sherbrooke, Canada; Computational Chemistry & Photonics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.05.2012 11:30<br><strong>Summary</strong>: "The main goal of the new attosecond (asec=10**-18s) science is the visualization, control and manipulation of electrons on their natural time scale, the asec (152 asecs being the orbital period of the H atom). High order harmonic generation (HHG) in atoms and Molecular High Order Harmonic Generation (MHOHG) in molecules driven by intense ultrashort low frequency laser pulses are the current main source of asec pulses.The mechanism for generation of harmonics is based on the three-step model of tunnelling ionization, acceleration and collision-recollision of the ionized electron with parent or neighbour ions [1]. So far only linearly polarized isolated asec pulses have been generated for which the recollision model predicts maximum energies [2]. Current research on asec pulse generation is focused on the polarization state in MHOHG [3]. Modelling of laser-molecule interactions in the nonlinear nonperturbative regime requires extensive (expensive) numerical solutions of Time-Dependent Schroedinger Equations (TDSE) from which one can study recollision dynamics with ultrashort intense circularly polarized laser pulses in order to produce circular asec pulses. Semiclassical models of laser induced recollision allow for determining the effect of various laser parameters such as polarization, intensity and duration of circularly polarized asec pulses. Such pulses due to their large band width will allow for the creation of circular coherent electron wave packets (CEWP), ie, « spinning » electrons. Chemistry and biology have lived through 2 centuries of molecular « structure ». Asec pulses will finally allow scientists to study molecular « function » on the electron`s natural time scale, the asec?"[1] PB Corkum, Physics Today, March 2011,p.16[2] AD Bandrauk, S Chelkowski, Intnl Rev Atom Molec Phys, 2, 1-22 (2011).[3] AD Bandrauk, KJ Yuan, J Phys B, S 45, 074001 (2012)Thu, 03 Sep 2015 23:02:13 +0200http://www.mpq.mpg.de/events/7088/5381003?14413141332015-09-03T23:02:13+02:00"Recent experiments with ions on microfabricated surface traps."
http://www.mpq.mpg.de/events/7087/5381003
<strong>Speaker</strong>: Dr. Yves Colombe, National Institute of Standards and Technology, Boulder, USA<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 14.05.2012 13:00<br><strong>Summary</strong>: "In this talk I will report on recent progress made at NIST Boulder in the manipulation of ions using microfabricated surface traps. A first experiment performs a laser-less two qubit logic gate, taking advantage of the high magnetic field gradients that can be generated on ion chips. A second experiment, operated at cryogenic temperature, shows the exchange of a single quantum of vibration between two ions trapped 40 micrometers apart. Lastly, I will describe an experiment where the anomalous heating rate of a trapped ion is reduced by a factor of 100 after in-situ cleaning of the surface of the trap."Thu, 03 Sep 2015 23:02:12 +0200http://www.mpq.mpg.de/events/7087/5381003?14413141322015-09-03T23:02:12+02:00"Fundamental physics with ultra-cold neutrons at the FRM-2."
http://www.mpq.mpg.de/events/7086/5381003
<strong>Speaker</strong>: Prof. Dr. Peter Fierlinger, Technische Universität München; Excellence-Cluster ‚Universe’<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.05.2012 11:30<br><strong>Summary</strong>: "Ultra-cold neutrons (UCN) are a unique tool to measure fundamental properties of nature. Due to the neutron’s comparably simple composition, it is also a favored system to perform searches for a permanent electric dipole moment (EDM) of a fundamental system that violates time reversal symmetry. Such a phenomenon is required in most theories in particle physics to explain the excess of matter versus antimatter in the Universe, a problem which the standard model of particle physics fails to explain by eight orders of magnitude. The search for EDMs is already ongoing for many years in different systems and has already ruled out or restricted many theories and already probes energy scales beyond the LHC. In this talk I will give an overview of the research with such very slow neutrons and focus on a new flagship experiment that is currently being set up at the FRM-2 reactor in Garching to measure the neutron EDM with a sensitivity of 10-28 e.cm. This corresponds to a larger than a factor 100 improvement, which requires next to the strongest possible source of UCN also an elaborate effort to control systematic effects in small magnetic and electric fields."Thu, 03 Sep 2015 23:02:12 +0200http://www.mpq.mpg.de/events/7086/5381003?14413141322015-09-03T23:02:12+02:00"Ultrahigh plasma acceleration by lasers possibly for nuclear energy without dangerous radiation."
http://www.mpq.mpg.de/events/7085/5381003
<strong>Speaker</strong>: Prof. Dr. Heinrich Hora, University of New South Wales; Theoretical Physics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 24.04.2012 11:30<br><strong>Summary</strong>: "Sauerbrey’s measurement [1] of ultrahigh acceleration of plasma blocks by 1020 cm/s2 with ps laser pulses at very high intensity – confirmed by Földes et al. [2] – are 10,000 times higher than any acceleration with ns laser pulses. At ns, thermal pressure with losses and delays dominates the interaction, while the ps case is dominated by the instantly acting nonlinear (ponderomotive) force. The ps acceleration of 1020 cm/s2 was theoretically and numerically predicted in 1978 [3] (see p. 179). The mechanism is different from acceleration of ion beams due to relativistic self-focusing which has to be avoided using very high contrast ratio laser pulses. Based on the measurements [1,2] the mechanism of the ps acceleration in contrast to that with ns pulses can now be understood as the non-thermal >99% efficient transfer of optical energy into macroscopic motion of the irradiated electron cloud in the space charge neutral plasma, where the inertia is determined by the cloud of the attracted ions. After this plasma block acceleration has been clarified by several further measurements [4], this can be applied to the picosecond irradiation of uncompressed solid DT fusion fuel by side-on igniton [5] of a fusion flame. Computations for igniting solid density hydrogen-boron(11) is only less than 10 times more difficult and may lead to fusion energy production with less radioactivity than from burning coal [6]." [1] Sauerbrey R. Physics of Plasmas 3: 4712 (1996)[2] Földes I B, Bakos J S, Gal, K. et al. Laser Physics 10: 264 (2000)[3] Hora H Physics of Laser Driven Plasmas. New York: John Wiley 1981[4] Hora H., Badziak J., Jie Zhang, K. Jungwirth, K. Rohlena et al. Physics of Plasmas 14: 072701 (2007)[5] Hora H, Miley G H, Flippo K, Lalousis P et al. Laser and Particle Beams 29, 353 (2011)[6] Hora H, Miley G H, He X. et al.2010 Energy and Environmental Science 3: 479 (2010)[7] Hora H, Miley, G H, Yang X., Lalousis P. Astrophysics and Space Science 336: 225 (2011)Thu, 03 Sep 2015 23:02:12 +0200http://www.mpq.mpg.de/events/7085/5381003?14413141322015-09-03T23:02:12+02:00"High power laser research at the Townes Institute, ultrafast lasers and all."
http://www.mpq.mpg.de/events/7084/5381003
<strong>Speaker</strong>: Prof. Dr. Martin C. Richardson, University of Central Florida, The College of Optics & Photonics<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 03.04.2012 11:30<br><strong>Summary</strong>: "The seminar will describe latest work in high power fiber and solid state laser development, new investments in next generation lasers, high power OPCPA single cycle laser development, and some applications. It will also summarize the continuing build out of the Townes Laser Institute."Thu, 03 Sep 2015 23:02:11 +0200http://www.mpq.mpg.de/events/7084/5381003?14413141312015-09-03T23:02:11+02:00"Recent developments in atomic and diamond magnetometers and their applications in NMR."
http://www.mpq.mpg.de/events/7083/5381003
<strong>Speaker</strong>: Prof. Dr. Dmitry Budker, U.C. Berkeley Physics Department, LBNL Nuclear Science Division<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 19.03.2012 10:00<br><strong>Summary</strong>: "A lot is going on in the magnetometry field, with new techniques sprouting that allow ever-improved sensitivity and spatial resolution. One of the latest raves is magnetometers based on color centers in diamond that consist of a substitutional nitrogen atom and a vacancy in a diamond lattice.To measure Earth’s magnetic field, an orange laser beam is directed at a layer of sodium 90 kilometers above the planet. This presentation will cover recent applications of magnetometers to nuclear magnetic resonance without magnets (!) and other magnetometer adventures ranging from the search for plant biomagnetism to measuring magnetic fields in the mesosphere using sodium laser guide stars."Thu, 03 Sep 2015 23:02:11 +0200http://www.mpq.mpg.de/events/7083/5381003?14413141312015-09-03T23:02:11+02:00"Quantum Error Correction and the Future of Solid State Qubits."
http://www.mpq.mpg.de/events/7082/5381003
<strong>Speaker</strong>: Prof. Dr. David DiVincenzo, RWTH Aachen und am Forschungszentrum Jülich<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 07.02.2012 12:30<br><strong>Summary</strong>: Quantum information theory provides a very challenging but well defined goal for the further development of solid state qubits: achieve high enough fidelity so that fault-tolerant, error corrected quantum computation in networks of these qubits becomes possible. I will review the development and essential textbook facts about quantum error correcting codes, but will discuss developments not yet found in the books that make solid state fault tolerance much more tangible: gate transversality is replaced by code deformation, and concatentation (with the concomitant requirement for long-distance couplings) is replaced by regular, extendable lattice structures of locally interacting qubits. This new point of view points us to a concrete concept of the solid state structure that we need, and indicates fidelity targets, around 99%, which do not appear as unreachable as they once were. Thu, 03 Sep 2015 23:02:11 +0200http://www.mpq.mpg.de/events/7082/5381003?14413141312015-09-03T23:02:11+02:00"Optical Control of Currents along Nanoscale Junctions."
http://www.mpq.mpg.de/events/7081/5381003
<strong>Speaker</strong>: Dr. Ignacio Franco, Fritz-Haber-Institut, Berlin<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 31.01.2012 14:30<br><strong>Summary</strong>: In this talk, I will first describe a general class of symmetry breaking laser control scenarios capable of generating phase controllable transport in spatially symmetric systems. Then, I will discuss the applicability of such scenarios in inducing currents along nanoscale junctions through explicit computations of the laser-induced dynamics along trans-polyacetylene oligomers coupled to metallic leads. A point of focus will be the effect of electronic decoherence due to electron-vibrational couplings on our ability to exert the laser control. Last, I will introduce a way to induce ultrafast currents along nanoscale junctions that is based on the dynamic Stark effect instead of near resonance photon absorption. Through computations, I will show that Stark shifts can be used to bridge the energy gap of the trans-polyacetylene oligomers and generate net phase controllable currents in junctions. The effect is remarkably robust to decoherence effects and leads to almost complete control of the electronic dynamics even in the presence of strong vibronic couplings. Thu, 03 Sep 2015 23:02:11 +0200http://www.mpq.mpg.de/events/7081/5381003?14413141312015-09-03T23:02:11+02:00"Optically Probing Quantum States in Artificial Atoms and Molecules."
http://www.mpq.mpg.de/events/7080/5381003
<strong>Speaker</strong>: Prof. Dr. Jonathan Finley, Walter-Schottky-Institut, München<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 31.01.2012 12:30<br><strong>Summary</strong>: The development of “hybrid” quantum nanosystems combining electronic and photonic functionality opens the door to manipulate light-matter interactions and engineer quantum properties in hand made optically active nano-materials. This talk will give an overview of several research themes that focus on this kind of systems. Specific examples include the electro-optical preparation, manipulation and readout of the spin of single electrons and holes in artificial atoms and molecules and the investigation of coupling to the solid-state environment.Thu, 03 Sep 2015 23:02:10 +0200http://www.mpq.mpg.de/events/7080/5381003?14413141302015-09-03T23:02:10+02:00Der Vortrag muss krankheitsbedingt entfallen!
http://www.mpq.mpg.de/events/7079/5381003
<strong>Speaker</strong>: Prof. Dr. Jens Biegert, The Institute of Photonics Sciences, Spanien (ICFO)<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 24.01.2012 12:30Thu, 03 Sep 2015 23:02:10 +0200http://www.mpq.mpg.de/events/7079/5381003?14413141302015-09-03T23:02:10+02:00"Quantum Experiments with Massive Mechanical Objects: Pushing the Frontiers of Quantum Optics."
http://www.mpq.mpg.de/events/7078/5381003
<strong>Speaker</strong>: Prof. Dr. Markus Aspelmeyer, Universität Wien<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 11.01.2012 12:30<br><strong>Summary</strong>: Massive mechanical objects are now becoming available as new systems for quantum science. They combine features that allow unique approaches in both quantum foundations and quantum applications. For example, their size and mass provides access to a hitherto untested parameter regime of macroscopic quantum physics. At the same time, the on-chip integrability of nano- and micromechanics, together with their flexibility to couple to different physical systems, offers a novel perspective for quantum information processing architectures.Quantum optics provides a high-precision toolbox to enter and to control the quantum regime of the motion of such mechanical devices. I will briefly highlight the recent developments and discoveries in the field. This includes our recent progress towards generating optomechanical quantum entanglement, which is at the heart of Schroedinger’s cat paradox, as well as some surprising technology spin-offs that we have encountered. I will also discuss the fascinating perspectives and challenges when pushing towards quantum experiments with truly massive mechanical objects, in particular the possibility to explore the interface between quantum physics and (quantum) gravity in table-top quantum optics experiments.Thu, 03 Sep 2015 23:02:10 +0200http://www.mpq.mpg.de/events/7078/5381003?14413141302015-09-03T23:02:10+02:00"The two-dimensional Bose gas: Thermodynamics and beyond"
http://www.mpq.mpg.de/events/7077/5381003
<strong>Speaker</strong>: Prof. Dr. Jean Dalibard, Laboratoire Kastler Brossel, Paris<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.01.2012 12:30<br><strong>Summary</strong>: A two-dimensional Bose fluid is a remarkably rich many-body system, which allows one to revisit several features of quantum statistical physics. Firstly, the role of thermal fluctuations is enhanced compared to the 3D case, which destroys the ordered state associated with Bose–Einstein condensation. However interactions between particles can still cause a superﬂuid transition, thanks to the Berezinskii–Kosterlitz–Thouless mechanism. Secondly, the weakly interacting Bose gas in 2D must be scale-invariant, a remarkable feature that manifests itself in the very simple form taken by the equation of state of the fluid. In this talk I will summarize the recent experimental progress in the investigation of 2d atomic gases, and draw some comparisons with other planar fluids such as exciton-polariton gases, which also provide spectacular illustrations of low dimensional many-body physics. Thu, 03 Sep 2015 23:02:09 +0200http://www.mpq.mpg.de/events/7077/5381003?14413141292015-09-03T23:02:09+02:00"The two-dimensional Bose gas: Thermodynamics and beyond"
http://www.mpq.mpg.de/events/7076/5381003
<strong>Speaker</strong>: Prof. Dr. Jean Dalibard, Laboratoire Kastler Brossel, Paris<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.01.2012 12:30<br><strong>Summary</strong>: A two-dimensional Bose fluid is a remarkably rich many-body system, which allows one to revisit several features of quantum statistical physics. Firstly, the role of thermal fluctuations is enhanced compared to the 3D case, which destroys the ordered state associated with Bose–Einstein condensation. However interactions between particles can still cause a superﬂuid transition, thanks to the Berezinskii–Kosterlitz–Thouless mechanism. Secondly, the weakly interacting Bose gas in 2D must be scale-invariant, a remarkable feature that manifests itself in the very simple form taken by the equation of state of the fluid. In this talk I will summarize the recent experimental progress in the investigation of 2d atomic gases, and draw some comparisons with other planar fluids such as exciton-polariton gases, which also provide spectacular illustrations of low dimensional many-body physics. Thu, 03 Sep 2015 23:02:09 +0200http://www.mpq.mpg.de/events/7076/5381003?14413141292015-09-03T23:02:09+02:00"Molecular Sciences: The Dynamical Perspective."
http://www.mpq.mpg.de/events/7075/5381003
<strong>Speaker</strong>: Prof. Dr. Albert Stolow, National Research Council, Ottawa<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.01.2012 12:30<br><strong>Summary</strong>: Ultrafast laser science has led to significant progress in molecular dynamics studies, particularly for the difficult but general case of non-Born-Oppenheimer dynamics. Quantum control methods further enhance molecular dynamics studies by permitting direct Molecular Frame measurements. As laser fields get stronger, a sub-cycle (attosecond) physics emerges, leading to new probes of driven multi-electron dynamics in polyatomic molecules. In condensed phases, ultrafast lasers permit the ‘triggered’ unzipping of double helix DNA, potentially leading to ‘light-induced genomics’, as well as simplified approaches to label-free CARS microscopy of live cells and tissues. Thu, 03 Sep 2015 23:02:08 +0200http://www.mpq.mpg.de/events/7075/5381003?14413141282015-09-03T23:02:08+02:00"Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators."
http://www.mpq.mpg.de/events/7074/5381003
<strong>Speaker</strong>: Manuel Endres, MPI für Quanten Optik, Garching, Abt. Quanten-Vielteilchensysteme<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.01.2012 13:15<br><strong>Summary</strong>: Quantum phases of matter are characterized by the underlying correlations of the many-body system. Although this is typically captured by a local order parameter, it has been shown that a broad class of many-body systems possesses a hidden nonlocal order. In the case of bosonic Mott insulators, the ground state properties are governed by quantum fluctuations in the form of correlated particle-hole pairs that lead to the emergence of a nonlocal string order in one dimension. By using high-resolution imaging of low-dimensional quantum gases in an optical lattice, we directly detect these pairs with single-site and single-particle sensitivity and observe string order in the one-dimensional case. Thu, 03 Sep 2015 23:02:08 +0200http://www.mpq.mpg.de/events/7074/5381003?14413141282015-09-03T23:02:08+02:00"Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators."
http://www.mpq.mpg.de/events/7072/5381003
<strong>Speaker</strong>: Manuel Endres, MPI für Quanten Optik, Garching, Abt. Quanten-Vielteilchensysteme<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.01.2012 13:15<br><strong>Summary</strong>: Quantum phases of matter are characterized by the underlying correlations of the many-body system. Although this is typically captured by a local order parameter, it has been shown that a broad class of many-body systems possesses a hidden nonlocal order. In the case of bosonic Mott insulators, the ground state properties are governed by quantum fluctuations in the form of correlated particle-hole pairs that lead to the emergence of a nonlocal string order in one dimension. By using high-resolution imaging of low-dimensional quantum gases in an optical lattice, we directly detect these pairs with single-site and single-particle sensitivity and observe string order in the one-dimensional case. Thu, 03 Sep 2015 23:02:08 +0200http://www.mpq.mpg.de/events/7072/5381003?14413141282015-09-03T23:02:08+02:00"Extreme Localization of Electrons in Space and Time."
http://www.mpq.mpg.de/events/7073/5381003
<strong>Speaker</strong>: Dr. Peter Hommelhoff, MPI für Quanten Optik, Garching; Forschungsgruppe "Ultraschnelle Quantenoptik"<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 10.01.2012 12:30<br><strong>Summary</strong>: Waveform control of few-cycle laser pulses allows steering of electrons in atoms, molecules, and clusters in the gas phase, which has led to, for example, attosecond pulse generation and time-resolved imaging of molecular orbitals. We have observed strong-field effects from nanoscale metal tips [1], including re-scattering and strong carrier-envelope phase effects, which reveal themselves via matter wave interference in the time-energy domain [2]. This paves the way towards light-based steering of electrons in a solid-state system. In a separate experiment we have demonstrated guiding of electrons in a linear Paul trap [3], which might lead to a new quantum system. We will report on both experiments. [1] M. Schenk, M. Krüger, P. Hommelhoff, PRL 105, 257601 (2010) [2] M. Krüger, M. Schenk, P. Hommelhoff, Nature 475, 78 (2011) [3] J. Hoffrogge, R. Fröhlich, M. Kasevich, P. Hommelhoff, PRL 106, 193001 (2011) Thu, 03 Sep 2015 23:02:08 +0200http://www.mpq.mpg.de/events/7073/5381003?14413141282015-09-03T23:02:08+02:00"Chasing the Neutrino Mass."
http://www.mpq.mpg.de/events/7071/5381003
<strong>Speaker</strong>: Prof. Dr. Ernst-Wilhelm Otten, Universität Mainz<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 20.12.2011 12:30<br><strong>Summary</strong>: In the thirties of the last century Pauli and Fermi had solved the apparent violation of conservation laws in nuclear beta-decay by introducing a so far undetected, weakly interacting, neutral, and practically mass less particle – the neutrino. Twenty years later Reines finally could detect this missing particle in beta-decay by experiment. The further exploration of neutrino properties and interactions revealed great discoveries and surprises: parity violation, the existence of three neutrino flavours, and finally, at the turn of the century, the oscillation between neutrino flavours by superposition of three mass eigenstates with tiny mass differences. But the question about the absolute neutrino mass is still open. The experimental part of the talk will focus on the neutrino mass searches based on terrestrial experiments within the KATRIN collaboration at Forschungszentrum Karlsruhe.Thu, 03 Sep 2015 23:02:07 +0200http://www.mpq.mpg.de/events/7071/5381003?14413141272015-09-03T23:02:07+02:00"Optics beyond the Abbe limit: molecular resolution imaging by farfield light microscopy."
http://www.mpq.mpg.de/events/7070/5381003
<strong>Speaker</strong>: Prof. Dr. Christoph Cremer, Universität Heidelberg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 13.12.2011 12:30<br><strong>Summary</strong>: New developments in far-field light microscopy made possible to radically overcome the diffraction limit (ca. 200 nm laterally, 600 nm along the optical axis) of conventional far field microscopy. Presently, three principal “nanoscopy” families have been formed: “Nanoscopy” based on highly focused laser beams; nanoscopy based on Structured Illumination Excitation (SIE); and nanoscopy allowing superresolution even in the case of homogeneous excitation. With such techniques, it has become possible to analyze the spatial distribution of fluorescent molecules on surfaces and in biostructures with a greatly increased light optical resolution down to a few nanometers, corresponding to 1/100 of the exciting wavelength, and with single target/molecule localization accuracies down to a few Angstrom.Thu, 03 Sep 2015 23:02:07 +0200http://www.mpq.mpg.de/events/7070/5381003?14413141272015-09-03T23:02:07+02:00"Ultracold quantum gases in triangular and hexagonal optical." lattices: unconventional magnetism and Graphene like physics
http://www.mpq.mpg.de/events/7069/5381003
<strong>Speaker</strong>: Prof. Dr. Klaus Sengstock, Universität Hamburg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 06.12.2011 12:30<br><strong>Summary</strong>: "Scientific News" (copied from: http://photon.physnet.uni-hamburg.de/de/ilp/sengstock/)"The research in our group mainly concentrates on two major topics. Experiments dedicated to the field of ultracold quantum gases are complemented by research activities in the field of fibre laser development and state-of-the-art ultra-sensitive spectroscopy.At temperatures close to absolute zero neutral atoms offer an ultimate degree of control over all system parameters. Bosonic, fermionic and mixed systems in trapping potentials of different geometry including e.g. optical lattices and hollow core photonic crystal fibres are realized in our group and offer the possibility to mimic pure quantum mechanical model systems over a wide range of interaction and correlation regimes.We are especially interested in laser cooling techniques, the physics of multi-component system pointing towards the investigation of e.g. quantum magnetism in frustrated geometries and other exotic quantum phases like e.g. composite particles made out of Bosons and Fermions in optical lattices.You will find descriptions of the individual research projects here."Thu, 03 Sep 2015 23:02:07 +0200http://www.mpq.mpg.de/events/7069/5381003?14413141272015-09-03T23:02:07+02:00"Interaction-based quantum metrology and the Heisenberg limit."
http://www.mpq.mpg.de/events/7068/5381003
<strong>Speaker</strong>: Prof. Dr. Morgan Mitchell, The Institute of Photonic Sciences ( ICFO), Barcelona<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 29.11.2011 12:30<br><strong>Summary</strong>: Quantum Metrology uses entanglement and other quantum resources to improve the sensitivity of interferometric measurements. Strongly-interacting light-matter systems, or "quantum interfaces", offer several routes to improvedsensitivity, including quantum non-demolition measurements, squeezing-enhanced optical readout of atomic sensors, and interaction-based measurements. I will describe recent experimental work that applies these quantum techniques in optical magnetometry, including sensitivity enhancements using optical entanglement, generation of squeezed states in magnetically-sensitive atomic ensembles, and interaction-based spin measurements that scale better than the so-called ''Heisenberg limit'' of measurement sensitivity. Thu, 03 Sep 2015 23:02:07 +0200http://www.mpq.mpg.de/events/7068/5381003?14413141272015-09-03T23:02:07+02:00"A deterministic few-fermion system for the quantum simulation of few-body systems."
http://www.mpq.mpg.de/events/7067/5381003
<strong>Speaker</strong>: Prof. Dr. Selim Jochim, Universität Heidelberg<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 22.11.2011 12:30<br><strong>Summary</strong>: Strongly correlated few-body systems are the building blocks of nature, with atoms and nuclei being prominent examples. We have realized artificial few-body systems consisting of 1-10 atoms in a tightly confining trap inwhich all quantum mechanical degrees of freedom can be controlled. In spite of this extraordinary control these systems are isolated from the environment on the time scale of experiments (up to 60s). We thus have a generic model system that allows us to study few-body theories developed for example in nuclear physics with exceptional flexibility [1]. While a system of two strongly interacting particles can be solved analytically, this is no longer the case for three or more. In this way conceptually very simple systems can be studied experimentally, for which no theoretical prediction exists. [1] F. Serwane et al., Science 332, 336 (2011Thu, 03 Sep 2015 23:02:06 +0200http://www.mpq.mpg.de/events/7067/5381003?14413141262015-09-03T23:02:06+02:00"Relaxation dynamics in many body quantum system."
http://www.mpq.mpg.de/events/7066/5381003
<strong>Speaker</strong>: Prof. Dr. Jörg Schmiedmeyer, Vienna Center for Quantum Science and Technology (VCQ), Atominstitut, TU-Wien<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 15.11.2011 12:30<br><strong>Summary</strong>: Understanding non-equilibrium dynamics of many-body quantum systems is crucial for understanding many fundamental and applied physics problems ranging from decoherence and equilibration to the development of future quantum technologies such as quantum computers which are inherently non-equilibrium quantum systems. One of the biggest challenges is that there is no general approach to characterize the resulting quantum states, such as the analogue of order parameters in equilibrium systems. Thu, 03 Sep 2015 23:02:06 +0200http://www.mpq.mpg.de/events/7066/5381003?14413141262015-09-03T23:02:06+02:00"Sisyphus Cooling of Polyatomic Molecules ."
http://www.mpq.mpg.de/events/7065/5381003
<strong>Speaker</strong>: Martin Zeppenfeld, MPI für Quantenoptik, Garching, Abt. Quantendynamik<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.11.2011 12:30<br><strong>Summary</strong>: From the first cold-molecule experiments about a decade ago, a general approach to cool trapped molecular ensembles akin to laser cooling for alkali atoms has been a much sought-after goal. In this talk, I will present the experimental realization of opto-electrical cooling, a general Sisyphus-type cooling scheme for polar molecules. As a first result, electrically trapped methyl-fluoride molecules have been cooled by a factor 4.6 to 77mK, resulting in an increase in phase-space density by a factor 7. Improvements in our trap design will allow cooling to sub-mK temperatures and beyond, opening a viable direct route towards a molecular BEC starting from a warm ensemble for a broad range of molecular species.Thu, 03 Sep 2015 23:02:06 +0200http://www.mpq.mpg.de/events/7065/5381003?14413141262015-09-03T23:02:06+02:00"Quantum computers: potential and limitations."
http://www.mpq.mpg.de/events/7064/5381003
<strong>Speaker</strong>: Dr. Maarten van den Nest, MPI für Quantenoptik, Garching, Abt. Theorie<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 08.11.2011 12:30<br><strong>Summary</strong>: Why do quantum computers outperform classical ones? Is this due to the presence of entanglement? interference? non-commutativity? ... Understanding the relation between quantum and classical computation is a great challenge, both of fundamental and practical importance. In the field of classical simulations, the goal is to identify quantum computations that can be simulated efficiently on a classical computer and to understand which ingredients are responsible for the existence of such simulations. In this talk we discuss a selection of standard results and our own work in this topic. This includes e.g. classical simulations of certain highly entangled computations, the surprising power of commuting quantum operations and the existence of classical simulations of the quantum Fourier transform.Thu, 03 Sep 2015 23:02:06 +0200http://www.mpq.mpg.de/events/7064/5381003?14413141262015-09-03T23:02:06+02:00"Precise spectroscopy of the molecular hydrogen."
http://www.mpq.mpg.de/events/7063/5381003
<strong>Speaker</strong>: Prof. Dr. Krzysztof Pachucki, Universität Warschau<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 25.10.2011 11:30<br><strong>Summary</strong>: Recent advances in quantum electrodynamic theory and computational techniques for diatomic molecular systems make available the very accurate theoretical predictions for the hydrogen molecule and its isotopomers. Apart from testing fundamental interactions at the atomic scale, comparison with experimental values for rovibrational levels indicates limited applicability of the relativistic quantum chemistry and demonstrates the importance of QED effects. I will review recent progress in the theoretical description of simple molecular systems and present comparison with the most recent measurements performed at ETH Zurich and VU University of Amsterdam. Thu, 03 Sep 2015 23:02:05 +0200http://www.mpq.mpg.de/events/7063/5381003?14413141252015-09-03T23:02:05+02:00"Laser-plasma acceleration of electrons and protons."
http://www.mpq.mpg.de/events/7062/5381003
<strong>Speaker</strong>: Prof. Dr. Claes-Göran Wahlström, Universität Lund, Schweden<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 18.10.2011 11:30<br><strong>Summary</strong>: Laser pulses with very short duration and ultra-high peak power can today be efficiently produced with compact lasers. When such pulses are focused, extreme optical intensities are obtained. In their interaction with matter a wide range of exciting phenomena appears and novel fields of investigations and applications become possible. The lecture will concentrate on compact electron and ion acceleration, and some of their potential applications. Examples of results obtained within these areas at the Lund Laser Centre will be presented. Thu, 03 Sep 2015 23:02:05 +0200http://www.mpq.mpg.de/events/7062/5381003?14413141252015-09-03T23:02:05+02:00"Supernovae, entanglement and falling apples: experiments with Bose-Einstein condensates."
http://www.mpq.mpg.de/events/7061/5381003
<strong>Speaker</strong>: Dr. Paul Altin, Australian National University, Canberra<br><strong>Room</strong>: Herbert Walther Lecture Hall<br><br><strong>Date</strong>: 17.10.2011 09:00<br><strong>Summary</strong>: In the last decade and a half, experiments with Bose-Einstein condensates by groups the world over have explored new regimes in condensed matter and atomic physics, tested foundations of quantum mechanics and promised applications from precision metrology to quantum computing. In this talk, I will present three experiments encompassing a variety of BEC physics. I will describe our progress towards squeezing-enhanced interferometry beyond the classical limit, and present results from a BEC gravimeter using large-momentum-transfer beamsplitting. I will also discuss our recent work on the 'bosenova' phenomenon: the collapse of Bose-Einstein condensates with attractive interactions. Thu, 03 Sep 2015 23:02:05 +0200http://www.mpq.mpg.de/events/7061/5381003?14413141252015-09-03T23:02:05+02:00New concepts for the development of carbon nanotube materials for advanced photonics applications
http://www.mpq.mpg.de/events/7060/5381003
<strong>Speaker</strong>: Igor Bondarev, North Carolina Central University<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 17.08.2011 13:00<br><strong>Summary</strong>: Like all nanostructures, carbon nanotubes have interesting electromagnetic properties in the near field. The electromagnetic field near the cylindrical nanotube surface is affected by the electronic band structure, surface conductivity, and surface curvature of the nanotube. As a result, the interactions between the surface electromagnetic modes of the nanotube and, say, a surface excitonic state, or an atom (ion, molecule) doped into the nanotube have specific behaviors that have not been deeply explored thus far.Thu, 03 Sep 2015 23:02:05 +0200http://www.mpq.mpg.de/events/7060/5381003?14413141252015-09-03T23:02:05+02:00Quantum communication with integrated optics
http://www.mpq.mpg.de/events/7059/5381003
<strong>Speaker</strong>: Prof. Dr. Christine Silberhorn, Universität Paderborn<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 26.07.2011 11:30<br><strong>Summary</strong>: Integrated optic devices – such as optical fibers, waveguides or linear optical circuits – in combination with pulsed quantum light and time-multiplexing configurations offer distinct advantages to realize photonic quantum systems for quantum information applications. The experimental setups get miniaturized, the spatial properties of generated quantum states are defined by the guiding geometries and networks are intrinsically stable. We present our toolbox for the realization of future quantum devices, including engineered genuine single-mode pulsed quantum light and a high dimensional quantum walk experiment.Thu, 03 Sep 2015 23:02:04 +0200http://www.mpq.mpg.de/events/7059/5381003?14413141242015-09-03T23:02:04+02:00Bose-Einstein Condensation of Photons
http://www.mpq.mpg.de/events/7058/5381003
<strong>Speaker</strong>: Prof. Dr. Martin Weitz, Institut für Angewandte Physik der Universität Bonn<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 21.07.2011 07:30Thu, 03 Sep 2015 23:02:04 +0200http://www.mpq.mpg.de/events/7058/5381003?14413141242015-09-03T23:02:04+02:00Single spins in diamond: from quantum computers to atomic sensors
http://www.mpq.mpg.de/events/7057/5381003
<strong>Speaker</strong>: Prof. Dr. Fedor Jelezko, Institute of Quantum Optics, Ulm University, Germany<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 19.07.2011 11:30<br><strong>Summary</strong>: Diamond is not only the king gemstone, but also a promising material in modern technology (which holds a promise to replace silicon) owing tounprecedented thermal conductivity, high charge carrier mobility and chemical inertness. Less known is that defects in diamond can be used for quantum information processing. Owing to their remarkable stability, colour centers in diamond have already found an application in quantum cryptography. Furthermore, it was shown that spin states associated with single nitrogen-vacancy defects can be detected optically. In this talk I will discuss recent progress regarding spin-based quantum information processing and atomic magnetometry using single spins in diamond.Thu, 03 Sep 2015 23:02:03 +0200http://www.mpq.mpg.de/events/7057/5381003?14413141232015-09-03T23:02:03+02:00Laser-driven atoms in a nano-lattice rebel against uniformity
http://www.mpq.mpg.de/events/7056/5381003
<strong>Speaker</strong>: Prof. Dr. Alexander Kaplan, John Hopkins University, Baltimore, USA<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 15.07.2011 11:30<br><strong>Summary</strong>: On a sub-wavelength scale, atoms in a crystal, i. e. an ordered lattice, are normally assumed to be almost uniformly excited by an incident light. An interatomic interaction produces then a uniform local field (different from that of incident laser) at each atom as well. This is a major assumption in the Lorentz-Lorenz theory of interaction of light with dense matter. We showed [1] that at certain critical conditions on the atomic density and dipole strength, a previously unexpected phenomenon emerges: the interacting atoms break the uniformity of interaction, and in a violent switch to a strong non-uniformity, their excitation and local field form nanoscale strata with a spatial period much shorter than that of laser wavelength, thus changing the entire paradigm of light-matter interaction. The most interesting effects can be observed for relatively small 1D-arrays or 2D lattices if the laser is almost resonant to an atomic quantum transition. The effects include huge local field enhancement at size-related resonances at the frequencies near the atomic line, so that the strata are readily controlled by laser tuning. A striking feature is that for the shortest strata, the nearest atomic dipoles counter-oscillate, which is reminiscent of anti-ferromagnetism of magnetic dipoles in Ising model.Thu, 03 Sep 2015 23:02:03 +0200http://www.mpq.mpg.de/events/7056/5381003?14413141232015-09-03T23:02:03+02:00Recent progress in quantum control of trapped ions
http://www.mpq.mpg.de/events/7055/5381003
<strong>Speaker</strong>: Dr. Dietrich Leibfried, National Institute of Standards, Boulder/USA<br><strong>Room</strong>: Herbert-Walther Hörsaal<br><br><strong>Date</strong>: 12.07.2011 11:30<br><strong>Summary</strong>: The push to implement quantum information processing (QIP) with trapped ions has led to a number of technological advances that can be leveraged towards this goal, but also allow for novel experimental approaches outside the original scope. The most spectacular example for the latter is the quantum-logic ion clock, at present the most precise frequency standard, with potential for further improvement. This talk will cover some of the recent advances in QIP with trapped ions at NIST and give a few examples besides the quantum logic ion clock that illustrate the potential of trapped ions for quantum simulations of complex designer Hamiltonians, quantum limited measurements and high resolution spectroscopy. Thu, 03 Sep 2015 23:02:03 +0200http://www.mpq.mpg.de/events/7055/5381003?14413141232015-09-03T23:02:03+02:002017-08-17T00:00:00+02:00