Summary form only given. The investigation of coherent superposition states for atoms interacting with external potentials allows a completely new class of experiments directed towards coherent trapping and guiding of neutral atoms. In addition, the process of decoherence, i.e., the collapse of superposition states, is one of the basic concepts for our understanding of the connection between classical and quantum physics. We study the creation and decay of superpositions of different components of the center-of-mass wavefunction of rubidium atoms in a one-dimensional near-resonant optical lattice. This makes it possible to gain insight into the dependence of decoherence processes on the coupling of the atoms to the light field. We discuss the dependence of the wave packet oscillations and echoes on experimental parameters (potential depth, light intensity and detuning, time delay, size of the shift, etc.). We compare our experimental results with numerical simulations of the echo effect. The observation of this new effect in the coherent wave packet motion of atoms trapped in optical potentials will allow us to selectively study the decoherence process and measure the decoherence time in regimes where this was previously impossible.Summary form only given. The investigation of coherent superposition states for atoms interacting with external potentials allows a completely new class of experiments directed towards coherent trapping and guiding of neutral atoms. In addition, the process of decoherence, i.e., the collapse of superposition states, is one of the basic concepts for our understanding of the connection between classical and quantum physics. We study the creation and decay of superpositions of different components of the center-of-mass wavefunction of rubidium atoms in a one-dimensional near-resonant optical lattice. This makes it possible to gain insight into the dependence of decoherence processes on the coupling of the atoms to the light field. We discuss the dependence of the wave packet oscillations and echoes on experimental parameters (potential depth, light intensity and detuning, time delay, size of the shift, etc.). We compare our experimental results with numerical simulations of the echo effect. The observation of this new effect in the coherent wave packet motion of atoms trapped in optical potentials will allow us to selectively study the decoherence process and measure the decoherence time in regimes where this was previously impossible.

Conference on Lasers and Electro-OpticsJan 1, 20000 citations

Long-time coherence in echo spectroscopy with π/2 - π - π/2 pulse sequence

Arseni Goussev, Philippe Jacquod

Motivated by atomic optics experiments, we investigate a class of fidelity functions describing the reconstruction of quantum states by time-reversal operations as ${M}_{\mathrm{Da}}(t)=|\ensuremath{\langle}\ensuremath{\psi}|{e}^{i{H}_{2}t/2}{e}^{i{H}_{1}t/2}{e}^{\ensuremath{-}i{H}_{2}t/2}{e}^{\ensuremath{-}i{H}_{1}t/2}|\ensuremath{\psi}\ensuremath{\rangle}|{}^{2}$. We show that the decay of ${M}_{\mathrm{Da}}$ is quartic in time at short times and that it freezes well above the ergodic value at long times, when ${H}_{2}\ensuremath{-}{H}_{1}$ is not too large. The long-time saturation value of ${M}_{\mathrm{Da}}$ contains easily extractable information on the strength of decoherence in these systems.Motivated by atomic optics experiments, we investigate a class of fidelity functions describing the reconstruction of quantum states by time-reversal operations as ${M}_{\mathrm{Da}}(t)=|\ensuremath{\langle}\ensuremath{\psi}|{e}^{i{H}_{2}t/2}{e}^{i{H}_{1}t/2}{e}^{\ensuremath{-}i{H}_{2}t/2}{e}^{\ensuremath{-}i{H}_{1}t/2}|\ensuremath{\psi}\ensuremath{\rangle}|{}^{2}$. We show that the decay of ${M}_{\mathrm{Da}}$ is quartic in time at short times and that it freezes well above the ergodic value at long times, when ${H}_{2}\ensuremath{-}{H}_{1}$ is not too large. The long-time saturation value of ${M}_{\mathrm{Da}}$ contains easily extractable information on the strength of decoherence in these systems.

arXiv:1006.0339Physical Review ANov 18, 20102 citations

Anomalous echoes in quantum systems

Gaetano Busiello, R. V. Saburova, F. S. Vagapova

Solid State CommunicationsFeb 1, 19970 citations

The Bose-Einstein Condensate and Cold Atom Laboratory

Kai Frye, Sven Abend, Wolfgang Bartosch +51 more

Abstract Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension and eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt and operate experimental setups on microgravity platforms. We describe the design of the payload, motivations for design choices, and capabilities of the Bose-Einstein Condensate and Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds on the heritage of previous devices operated in microgravity, features rubidium and potassium, multiple options for magnetic and optical trapping, different methods for coherent manipulation, and will offer new perspectives for experiments on quantum optics, atom optics, and atom interferometry in the unique microgravity environment on board the International Space Station.Abstract Microgravity eases several constraints limiting experiments with ultracold and condensed atoms on ground. It enables extended times of flight without suspension and eliminates the gravitational sag for trapped atoms. These advantages motivated numerous initiatives to adapt and operate experimental setups on microgravity platforms. We describe the design of the payload, motivations for design choices, and capabilities of the Bose-Einstein Condensate and Cold Atom Laboratory (BECCAL), a NASA-DLR collaboration. BECCAL builds on the heritage of previous devices operated in microgravity, features rubidium and potassium, multiple options for magnetic and optical trapping, different methods for coherent manipulation, and will offer new perspectives for experiments on quantum optics, atom optics, and atom interferometry in the unique microgravity environment on board the International Space Station.

arXiv:1912.04849EPJ Quantum TechnologyJan 4, 2021148 citations

{M}_{\mathrm{Da}}

is quartic in time at short times and that it freezes well above the ergodic value at long times, when ${H}_{2}\ensuremath{-}{H}_{1}$ is not too large. The long-time saturation value of

{M}_{\mathrm{Da}}

contains easily extractable information on the strength of decoherence in these systems.