A5010863225- Cold Atom Physics and Bose-Einstein Condensates
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Advanced Frequency and Time Standards
- Spectroscopy and Laser Applications
- Strong Light-Matter Interactions
- Quantum Information and Cryptography
- Physics of Superconductivity and Magnetism
- Quantum optics and atomic interactions
- Quantum many-body systems
- Quantum Mechanics and Applications
- Advanced Fiber Laser Technologies
- Topological Materials and Phenomena
- Laser Design and Applications
- Mechanical and Optical Resonators
- Scientific Measurement and Uncertainty Evaluation
- Atomic and Molecular Physics
- Orbital Angular Momentum in Optics
- Laser-Matter Interactions and Applications
- Radioactive Decay and Measurement Techniques
- Advanced Thermodynamics and Statistical Mechanics
- Photonic and Optical Devices
- Advanced Materials Characterization Techniques
- Theoretical and Computational Physics
- Semiconductor Lasers and Optical Devices
Universität Hamburg
2015-2024
Hamburg Centre for Ultrafast Imaging
2015-2024
Max Planck Institute for the Structure and Dynamics of Matter
2015-2024
University of Bremen
2013
University of Birmingham
2010
University of Bonn
1989-2007
Leibniz University Hannover
1995-2005
Centre National de la Recherche Scientifique
1995-1996
Institut d’Optique Graduate School
1995-1996
Institut für Technische und Angewandte Physik (Germany)
1989-1995
Dark solitons in cigar shaped Bose-Einstein condensates of Rubidium-87 are created by a phase imprinting method. Coherent and dissipative dynamics the has been observed.
Magnetism plays a key role in modern technology as essential building block of many devices used daily life. Rich future prospects connected to spintronics, next generation storage or superconductivity make it highly dynamical field research. Despite those ongoing efforts, the many-body dynamics complex magnetism is far from being well understood on fundamental level. Especially study geometrically frustrated configurations challenging both theoretically and experimentally. Here we present...
We present a universal method to create tunable, artificial vector gauge potential for neutral particles trapped in an optical lattice. The necessary Peierls phase of the hopping parameters between neighboring lattice sites is generated by applying suitable periodic inertial force such that does not rely on any internal structure particles. experimentally demonstrate realization potentials, which generate ground state superfluids at arbitrary non-zero quasi-momentum. furthermore investigate...
Cold atoms do geometry Electrons in solids populate energy bands, which can be simulated cold atom systems using optical lattices. The of the corresponding wave functions determines topological properties system, but getting a direct look is tricky. Fläschner et al. and Li measured detailed structure band hexagonal lattices, one resembling boron-nitride other graphene lattice. These techniques will make it possible to explore more complex situations that include effects interactions. Science...
Atom interferometers covering macroscopic domains of space-time are a spectacular manifestation the wave nature matter. Because their unique coherence properties, Bose-Einstein condensates ideal sources for an atom interferometer in extended free fall. In this Letter we report on realization asymmetric Mach-Zehnder operated with condensate microgravity. The resulting interference pattern is similar to one far field double slit and shows linear scaling time packets expand. We employ...
Time-periodic driving like lattice shaking offers a low-demanding method to generate artificial gauge fields in optical lattices. We identify the relevant symmetries that have be broken by function for purpose and demonstrate power of this making concrete proposals its application two-dimensional systems: show how tune frustration create control band touching points Dirac cones shaken kagome lattice. propose realization topological quantum spin Hall insulator spin-dependent hexagonal...
We report on the creation of ultracold heteronuclear molecules assembled from fermionic 40K and bosonic 87Rb atoms in a 3D optical lattice. Molecules are produced at Feshbach resonance both attractive repulsive sides resonance. precisely determine binding energy rf spectroscopy across characterize lifetime molecular sample as function magnetic field measure lifetimes between 20 120 ms. The efficiency molecule via association is measured found to decrease expected for more deeply bound molecules.
Albert Einstein's insight that it is impossible to distinguish a local experiment in "freely falling elevator" from one free space led the development of theory general relativity. The wave nature matter manifests itself striking way Bose-Einstein condensates, where millions atoms lose their identity and can be described by single macroscopic function. We combine these two topics report preparation observation condensate during fall 146-meter-tall evacuated drop tower. During expansion over...
Precision time references in space are of major importance to satellite-based fundamental science, global satellite navigation, earth observation, and formation flying.Here we report on the operation a compact, rugged, automated optical frequency comb setup sounding rocket under microgravity.The experiment compared two clocks, one based D 2 transition Rb, another hyperfine splitting Cs.This represents first clock space, which is an important milestone for future precision metrology.Based...
The theory of general relativity describes macroscopic phenomena driven by the influence gravity while quantum mechanics brilliantly accounts for microscopic effects.Despite their tremendous individual success, a complete unification fundamental interactions is missing and remains one most challenging important quests in modern theoretical physics.The STE-QUEST satellite mission, proposed as medium-size mission within Cosmic Vision program European Space Agency (ESA), aims testing with high...
Abstract Integer-valued topological indices, characterizing nonlocal properties of quantum states matter, are known to directly predict robust physical equilibrium systems. The Chern number, e.g., determines the quantized Hall conductivity an insulator. Using non-interacting fermionic atoms in a periodically driven optical lattice, here we demonstrate experimentally that number also far-from-equilibrium dynamics system. Extending respective proposal Floquet systems, measure linking...
We experimentally investigate and analyze the rich dynamics in F=2 spinor Bose-Einstein condensates of Rb87. An interplay between mean-field driven spin hyperfine-changing losses addition to interactions with thermal component is observed. In particular we measure conversion rates range 10^-12 cm^3/s for changing collisions within manifold spin-dependent loss 10^-13 collisions. From our data observe a polar behavior ground state Rb87, while F=1 be ferromagnetic. Furthermore see magnetization...
We observe a localized phase of ultracold bosonic quantum gases in 3-dimensional optical lattice induced by small contribution fermionic atoms acting as impurities Fermi-Bose gas mixture. In particular, we study the dependence this transition on $^{40}\mathrm{K}$ impurity concentration comparison to corresponding superfluid Mott-insulator pure $^{87}\mathrm{Rb}$ and find significant shift parameter. The observed is larger than expected based simple mean-field argument, which indicates that...
The occurrence of phase fluctuations due to thermal excitations in Bose-Einstein condensates (BECs) is studied for a variety temperatures and trap geometries. We observe the statistical nature appearance characterize dependence their average value on temperature, number particles, trapping potential. find pronounced very elongated traps broad temperature range. results are great importance realization BEC quasi-1D geometries, matter wave interferometry with BECs, as well coherence properties...
We find two types of moving dark soliton textures in elongated condensates: nonstationary kinks and proper solitons. The latter have a flat notch region we obtain the diagram their dynamical stability. At finite temperatures dynamically stable solitons decay due to thermodynamic instability. develop theory dissipative dynamics explain experimental data.
Over recent years, exciting developments in the field of ultracold atoms confined optical lattices have led to numerous theoretical proposals devoted quantum simulation problems e.g. known from condensed matter physics. Many those ideas demand experimental environments with non-cubic lattice geometries. In this paper, we report on implementation a versatile three-beam allowing for generation triangular as well hexagonal lattices. As an important step, superfluid–Mott insulator (SF–MI) phase...
We demonstrate numerically the efficient generation of vortices in Bose-Einstein condensates (BECs) by using a ``phase imprinting'' method. The method consists passing far-off-resonant laser pulse through an absorption plate with azimuthally dependent coefficient, imaging beam onto BEC, and thus creating corresponding nondissipative Stark-shift potential condensate phase shift. In our calculations we take into account experimental imperfections. also propose interference to detect coherently...