22.12.2010
	Professor Theodor W. Hänsch`s group among the "Top Ten" of Physics World
	The IOP (Institute of Physics, Bristol, UK) website physicsworld.com has announced this week the “top 10 breakthroughs” in physics for the year 2010. Place number 9 in the list is held by a new measurement of the proton size carried out by an international team led by Dr. Randolf Pohl, a member of the Laser Spectroscopy Division of Prof. Hänsch at the Max Planck Institute of Quantum Optics.
	11.11.2010
	A light transistor based on photons and phonons
	The ability to control the propagation of light is at the technological heart of today’s telecommunication society. Researchers in the Laboratory of Photonics and Quantum Measurement led by Prof. Tobias J. Kippenberg (now EPFL) have discovered a novel principle to accomplish this, which is based on the interaction of light (photons) with mechanical vibrations (phonons).
	24.10.2010
	Trapping charged particles with laser light
	In the past decades setups for trapping single particles have played a key role in high precision quantum measurements because they allow for an ultimate control of all important experimental parameters. However, up to now scientists had to choose between two alternative strategies...
	18.10.2010
	Breakdown of correlated tunneling
	Quantum systems do often behave differently from what we would expect intuitively and from our daily experience. One example is provided by the so-called Landau-Zener problem. It describes e.g. the tunneling of a quantum particle between two potential wells with an initial difference in potential energy that is gradually reversed over time....
	03.10.2010
	Quantum simulator and supercomputer at the crossroads
	Transitions between different phases of matter are a phenomenon occurring in everyday life. For example water – depending on its temperature – can take the form of a solid, a liquid or a gas. The circumstances that lead to the phase-transition of a substance are of fundamental interest in understanding emergent quantum phenomena of a many-particle system. In this respect, the ability to study phase transition between novel states of matter with ultracold atoms in optical lattices has raised the hope to answer open questions in condensed matter physics.
	18.08.2010
	Observing Quantum Particles in Perfect Order
	Ultracold atoms in optical lattices have evolved in the last years into an interdisciplinary tool for many-body solid state and quantum physics. But so far only limited possibilities were available to manipulate and to image the quantum gas on a microscopic scale. For the first time a team around Stefan Kuhr and Immanuel Bloch at MPQ has now succeeded in observing – atom by atom, lattice site by lattice site – such a strongly correlated system (Nature, 18 August 2010, DOI 10.1038/nature09378).
	05.08.2010
	Attosecond real-time Observation of a Quantum Hole
	An international team from the Laboratory for Attosecond Physics (www.attoworld.de), led by Prof. Ferenc Krausz at the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität in Munich, in collaborations with researchers from the United States and Saudi Arabia, have observed, for the first time, the quantum-mechanical behaviour occurring at the location in a noble gas atom where, shortly before, an electron had been ejected from its orbit. The researchers achieved this result using light pulses which last only slightly longer than 100 attoseconds.
	04.08.2010
	Single atoms for detecting extremely weak forces.
	Back in the 17th century the Dutch physicist Christiaan Huygens observed that the oscillation of two pendulums can synchronize if they have the possibility to interact with each other. Remarkably, this coupling doesn’t need to be strong and it might suffice, e.g. if they are mounted on the same wall. A large variety of oscillating systems show this kind of behaviour, nowadays called “injection locking”, ranging from organ pipes to lasers or electronic circuits.
	03.08.2010
	Cold atoms image microwave fields
	Microwaves are an essential part of modern communication technology. Mobile phones and laptops, for example, are equipped with integrated microwave circuits for wireless communication. Sophisticated techniques for measurement and characterization of microwave fields are an essential tool for the development of such circuits. A novel technique developed by a group of scientists around Prof. Theodor W. Hänsch (Max Planck Institute of Quantum Optics and Ludwig-Maximilians-Universität Munich (LMU)) and Prof. Philipp Treutlein (University of Basel) allows for the direct and complete imaging of microwave magnetic fields with high spatial resolution.
	30.07.2010
	Electrons in motion
	The world of atoms and molecules is very different from our everyday experience. We like to think of electrons as little particles. “And that is to some extent a valid picture” explains Marc Vrakking, director at the Max Born Institute in Berlin, “but quantum mechanics also forces us sometimes to consider the wave-nature of electrons”. Using this abstract representation of an electron, physicists can explain intriguing phenomena that in the end connect to our simple picture of the electron as a particle.
	08.07.2010
	How small is the proton?
	The proton – one of the universal building-blocks of all matter – is even smaller than had previously been assumed (Nature, 8 July 2010). This is the result obtained at the Paul-Scherrer-Institut (PSI) in Villigen (Switzerland) by an international research team, including scientists from the Max Planck Institute of Quantum Optics (MPQ) in Garching, the Ludwig-Maximilians-Universität (LMU) Munich and the Institut für Strahlwerkzeuge (IFWS) of the Universität Stuttgart (both from Germany).
	25.06.2010
	Delayed Time Zero
	When light is absorbed by atoms, the electrons become excited. If the light particles, so-called photons, carry sufficient energy, the electrons can be ejected from the atom. This effect is known as photoemission and was explained by Einstein more than hundred years ago. Until now, it has been assumed that immediately after the impact of the photons the electrons start moving out of the atom. ...
	23.06.2010
	Quantum Experiments in Microgravity
	At the beginning of the 20th century two theories have been developed that have completely changed our understanding of the forces of nature: General Relativity and Quantum Mechanics. Whereas General Relativity applies to the classical world and in particular describes the large structures in the universe, Quantum Mechanics rules the behaviour of the particles of the microcosm. ...
	10.06.2010
	A look into the Interior of Molecules
	In order to not only observe, but also really understand a chemical reaction, scientists have to know how electrons move within molecules. Until now it was technically impossible to observe how electrons move within a molecule, because they move so incredibly fast. However, a group of European researchers has now achieved this goal with the help of attosecond laser pulses. ...
	21.05.2010
	Quantum Communication in Random Networks
	Internet, networks of connections between Hollywood actors, etc, are examples of complex networks, whose properties have been intensively studied in recent times. The small-world property (that everyone has a few-step connection to celebrities), for instance, is a prominent result derived in this field. A group of scientists around Professor Cirac, Director at the Max Planck Institute of Quantum Optics (Garching near Munich) and Leader of the Theory Division, has now introduced complex networks in the microscopic, so called, quantum regime (Nature Physics, Advanced Online Publication, DOI:10.1038/NPHYS1665). ...
	17.05.2010
	Attosecond Physics becomes a Milestone
	It is a field that has moved beyond its infancy. The physics of ultra-short light pulses continues to go through a period of rapid development, which began in 2001 when a team headed by Prof. Ferenc Krausz was able, for the first time ever, to generate controlled light pulses which lasted for just a few attoseconds. One attosecond is 1 billionth of 1 billionth of a second. With this technology it is now possible to almost “photograph” the breakneck movements of electrons. As a result one can gain insight into the so-far largely unknown universe of elementary particles and hence an insight into the fundamental processes of nature. The scientific journal Nature has now selected attosecond physics as one of the most significant milestones in photonics (Nature Milestones: Photons, 1 May 2010).
	13.05.2010
	Quantum Dynamics of Matter Waves reveal exotic Multi-Body Collisions
	At extremely low temperatures atoms can aggregate into so-called Bose Einstein condensates forming coherent laser-like matter waves. Due to interactions between the atoms fundamental quantum dynamics emerge and give rise to periodic collapses and revivals of the matter wave field. A group of scientists led by Professor Immanuel Bloch (Chair of Experimental Physics at the Ludwig-Maximilians-Universität München (LMU) and Director of the Quantum Many Body Systems Division at the Max Planck Institute of Quantum Optics in Garching) has now succeeded to take a glance 'behind the scenes' of atomic interactions revealing the complex structure of these quantum dynamics. [...]
	13.05.2010
	Optical quantum transistor using single atoms
	Due to the continued miniaturization of computer chip components, we are about to cross a fundamental boundary where technology can no longer rely on the laws of the macroscopic world. With this in mind, scientists all over the world are researching technologies based on quantum effects that can be used to communicate and process information. One of the most promising developments in this direction are quantum networks in which single photons communicate the information between different nodes, e.g. single atoms. There the information can be stored and processed. A key element in these systems is Electromagnetically Induced Transparency (EIT), an effect that allows to radically change the optical properties of an atomic medium by means of light. [...]
	23.04.2010
	Interface between two different worlds: Atomic system couples to micromechanical oscillator
	Ultrakalte Atomwolken und mechanische Oszillatoren gehörten bisher zu unterschiedlichen Welten der Physik. Ein deutsch-französiches Forscherteam von der Ludwig-Maximilians-Unversität München (LMU), dem Max-Planck-Institut für Quantenoptik (MPQ, Garching bei München) und der Ecole Normale Supérieure (ENS, Paris) hat nun erstmals ein atomares Bose-Einstein-Kondensat an die Schwingungen eines mikromechanischen Oszillators gekoppelt (Physical Review Letters, DOI:10.1103/PhysRevLett. 104.143002). [...]
	01.04.2010
	Beyond the Quantum Limit
	The microcosm, the realm of quantum physics, is ruled by probability and chance. The behaviour of quantum particles cannot be predicted with certainty but only with certain probabilities given by quantum physics. This results in a so-called quantum noise, which fundamentally limits the precision of the most refined atomic clocks and interferometers. [...]
	31.01.2010
	Stroboscope for Quantum Physicists
	An important milestone towards the construction of a quantum computer is the generation and investigation of large quantum systems. To this end, photons – the particles of light – are promising candidates. Physicists of the group of Professor Harald Weinfurter (Ludwig Maximilian’s University Munich and Max Planck Institute of Quantum Optics, Garching, Germany) succeeded in developing a new method for the generation of intense, [...]
	14.01.2010
	Insight into Attosecond Physics
	Anyone delving deep into matter must reckon with the fact that the usual time scales cease to be valid in the tiny dimensions of molecules, atoms and electrons. Molecules react within femtoseconds (millionths of a billionth of a second). The motion of electrons in atoms is a thousand times faster still, lasting just a few attoseconds. [...]

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