Colloquia and Seminars

Our series of Colloquium Talks takes place from October till January and from April till July, on Tuesdays, at 2:30 p.m., at MPQ’s Herbert Walther Lecture Hall.

If you wish to view the live stream of the MPQ colloquium, please use the following link to subscribe to the corresponding mailing list. Detailed instructions will be sent to all subscribers.
14.10.2014 14:30
“Intense Femtosecond Laser Accelerated Electron Pulses for Single-Shot Ultrafast Electron Diffraction and Electron Deflectometry”
Professor Dr. Shuji Sakabe
University of Kyoto, Japan

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. A key issue in realizing single-shot ultrafast electron diffraction and electron deflectometry is the development of intense short electron pulse sources. Electrons accelerated by intense femtosecond laser pulses are promising for intense electron pulse sources. Our laboratory has been studying the physics of electron emission during and after laser-plasma interactions with the aim of developing higher intensity electron pulses. We have demonstrated femtosecond pulse compression of a laser-accelerated electron beam and a single shot diffraction image, directional intense electron emission from a metal wire target, and observed intense THz surface (Sommerfeld) wave traveling along the wire target with femtosecond electron deflectometry.

21.10.2014 14:30
“Many body localization and the breakdown of ergodicity in quantum systems”
Professor Dr. Ehud Altman
Weizmann Institute of Science, Israel

28.10.2014 14:30
“Generating multi-atom entanglement by quantum Zeno dynamics in an optical fiber microcavity”
Professor Dr. Jakob Reichel
Laboratoire Kastler Brossel de l’E.N.S., France

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. Recent developments in quantum technology show that powerful new forms of quantum dynamics can be obtained when this dichotomy is abandoned and environment coupling is used as part of the state generation. One intriguing example is Quantum Zeno Dynamics (QZD), which combines a unitary evolution U with a simultanous measurement that projects into a multidimensional subspace of the Hilbert space. The measurement effectively restricts the coherent evolution to that subspace. This results in quantum states that would be inaccessible to U alone, and which are potentially interesting for quantum engineering. Here we experimentally demonstrate the use of QZD, based on nondestructive measurement with a high-finesse optical cavity, to deterministically generate different multi-particle entangled states in an ensemble of 36 qubit atoms in less than 5 microseconds.

04.11.2014 14:30
“Creating topological matter by shaking atomic gases”
Professor Dr. Nathan Goldman
Collège de France (Paris, France) and Université Libre de Bruxelles (Belgium)

11.11.2014 14:30
“Condensed matter physics for quantum information”
Professor Dr. Charles Marcus
University of Copenhagen, Denmark

18.11.2014 14:30
“Demonstration of a passive, all-optical photonic device for scalable quantum networks”
Professor Dr. Barak Dayan
Weizmann Institute of Science, Israel

25.11.2014 14:30
“The Higgs Boson at the LHC - From discovery to measurements”
Professor D. Karl Jakobs
Universität Freiburg, Germany

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. Until the end of 2012 the experiments have collected a large data set corresponding to an integrated luminosity of about 25 fb-1 at centre-of-mass energies of 7 and 8 TeV. These data have been used to study the new particle in detail and to measure its properties. In this talk the discovery and the present status of the “profile” of the new particle are discussed. This includes a discussion on its compatibility with the predictions of the Standard Model of particle physics. Finally, an outlook on the next steps at the LHC, with focus on the search for new physics is given.

02.12.2014 14:30
“Quantum matter based on ultracold molecules”
Professor Dr. Jun Ye
University of Colorado, USA

10.12.2014 14:30
“Quantum communication, repeaters, qubit amplifiers and large entanglement”
Wednesday Colloquium!
Professor Dr. Nicolas Gisin
Universität Genf, Schweiz

Quantum communications is the art of transferring a quantum state from one location to a distant one. On the fundamental side, quantum communication is fascinating because it illustrates the power of entanglement and of non-local quantum correlations. On the application side, quantum communication is already relatively advanced with Quantum Random Number Generators and Quantum Key Distribution (QKD) systems having found niche markets. On the academic research side quantum communication has still a long way to go until a functional quantum repeater can extend the distances to continental scales. Quantum repeaters are based on quantum teleportation, the most fascinating application of entanglement. Additionally, quantum repeaters require quantum memories with memory times close to a second; this represents one grand challenge for quantum communication. Entangling two quantum memories, that is two crystal, raises the fascinating question of “what is large entanglement?”

16.12.2014 14:30
“Rotational cooling of polyatomic molecules”
Double Feature!
M. Sc. Rosa Glöckner
Max-Planck-Institut für Quantenoptik

16.12.2014 14:30
“An Aharonov-Bohm-type interferometer for determining Bloch band topology using ultracold atoms”
Double Feature!
M. Sc. Lucia Duca
Max-Planck-Institut für Quantenoptik

13.01.2015 14:30
“Certain aspects of entanglement in quantum many-body systems”
Professor Dr. Barbara Kraus
Universität Innsbruck, Austria

Many applications of quantum information rely on the potentiality of quantum systems to be correlated. For pure states, these correlations coincide with entanglement. Hence, the qualification and quantification of multipartite entanglement is one of the central topics within quantum information. However, as the dimension of the Hilbert space grows exponential with the number of considered subsystems, many very fundamental questions, in this context, are still unanswered. In this talk I will focus on some aspects of multipartite entanglement. In particular, I will present a generalization of the notion of maximally entangled bipartite states to the multipartite case and will demonstrate a new approach of quantifying entanglement of few--partite systems.

20.01.2015 14:30
“Light-matter-interfaces and nanophotonics with defect centers in diamond”
Double Feature!
Dr. Markus Weber
Max-Planck-Institut für Quantenoptik

20.01.2015 14:30
“Nanophotonics for quantum information and simulation”
Double Feature!
Dr. Alejandro Gonzalez-Tudela
Max-Planck-Institut für Quantenoptik

19.02.2015 14:30
To be announced
Professor Dr. Paul Corkum
University of Ottawa, Canada