Series on advances in quantum many-body theory

EXPERIMENTS WITH A RUBIDIUM BOSE-EINSTEIN CONDENSATE

E. Arimondo, Donatella Ciampini, O. Morsch, Jörg Helge Müller

Published Aug 1, 2002• 0 citations

Abstract

We report on three experiments based on a rubidium Bose-Einstein condensate. We examine the atomic micromotion of the condensate within a time dependent time orbiting potential. We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency diference between the two lattice beams. We have studied the photoionization processes of the condensate.

DOI: 10.1142/9789812777072_0004

Related papers

Coherent acceleration and Landau-Zener tunneling of Bose-Einstein condensates in 1-D optical lattices

O. Morsch, Jörg Helge Müller, Matteo Cristiani +1 more

We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency difference between the two lattice beams. For small values of the lattice well-depth, Bloch oscillations were observed. Landau-Zener tunneling out of the lowest lattice band, leading to a breakdown of the oscillations, was also studied. In order to allow in-trap measurements of these phenomena, we dynamically compensated for the intrinsic micromotion of the atoms in our time-orbiting potential trap.

arXiv:cond-mat/0103466Mar 22, 20011 citation

Rubidium Condensate for Quantum Optics Studies

E. Arimondo

Different experiments with Bose-Einstein rubidium condensates are presented in order to evidence the impact of condensate samples for the research in quantum optics and quantum physics. Measurements of the condensate free expansion, of the geometric forces acting on the condensate trapped into a time-orbiting-potential triaxial magnetic trap, of the acceleration of the condensate through a one-dimensional, off-resonant optical lattices and finally of the photoionization of the rubidium atoms composing the condensate are presented.

Fortschritte der PhysikMay 1, 20020 citations

A Bose-Einstein condensate in an optical lattice

Johannes Hecker Denschlag, J. E. Simsarian, Hartmut Häffner +6 more

We have performed a number of experiments with a Bose-Einstein condensate (BEC) in a one-dimensional optical lattice. Making use of the small momentum spread of a BEC and standard atom optics techniques, a high level of coherent control over an artificial solid-state system is demonstrated. We are able to load the BEC into the lattice ground state with a very high efficiency by adiabatically turning on the optical lattice. We coherently transfer population between lattice states and observe their evolution. Methods are developed and used to perform band spectroscopy. We use these techniques to build a BEC accelerator and a novel, coherent, large-momentum-transfer beam-splitter.

arXiv:cond-mat/0206063Journal of Physics B Atomic Molecular and Optical PhysicsJul 3, 2002369 citations

Bloch Oscillations and Mean-Field Effects of Bose-Einstein Condensates in 1D Optical Lattices

O. Morsch, Jörg Helge Müller, Matteo Cristiani +2 more

We have loaded Bose-Einstein condensates into one-dimensional, off-resonant optical lattices and accelerated them by chirping the frequency difference between the two lattice beams. For small values of the lattice well depth, Bloch oscillations were observed. Reducing the potential depth further, Landau-Zener tunneling out of the lowest lattice band, leading to a breakdown of the oscillations, was also studied and used as a probe for the effective potential resulting from mean-field interactions as predicted by Choi and Niu [Phys. Rev. Lett. 82, 2022 (1999)]. The effective potential was measured for various condensate densities and trap geometries, yielding good qualitative agreement with theoretical calculations.

arXiv:cond-mat/0108457Physical Review LettersSep 13, 2001548 citations

Experimental properties of Bose-Einstein condensates in one-dimensional optical lattices: Bloch oscillations, Landau-Zener tunneling, and mean-field effects

Matteo Cristiani, O. Morsch, Jörg Helge Müller +2 more

We report experimental results on the properties of Bose-Einstein condensates in one-dimensional optical lattices. By accelerating the lattice, we observed Bloch oscillations of the condensate in the lowest band, as well as Landau-Zener (LZ) tunneling into higher bands when the lattice depth was reduced and/or the acceleration of the lattice was increased. The dependence of the LZ tunneling rate on the condensate density was then related to mean-field effects modifying the effective potential acting on the condensate, yielding good agreement with recent theoretical work. We also present several methods for measuring the lattice depth and discuss the effects of the micromotion in the time-orbiting-potential trap on our experimental results.

arXiv:cond-mat/0202053Physical Review AJun 13, 2002208 citations

Ultracold rubidium atoms in periodic potentials

Robert Saers

This thesis includes both experimental and theoretical investigations, presented in a series of eight papers. The experimental part ranges from the construction procedures of an apparatus for Bose-Einstein condensates, to full scale experiments using three different set-ups for ultracold atoms in optical lattices. As one of the main themes of the thesis, an experimental apparatus for production of Bose-Einstein Condensates is under construction. A magneto-optically trapped sample, hosting more than 200 million 87Rb atoms, have successfully been loaded into a magnetic trap with high transfer rate. The lifetime of the sample in the magnetic trap is in the range of 9 s, and the atoms have been shown to respond to evaporative cooling. The experiment is ready for optimization of the magnetic trap loading, and evaporative cooling parameters, which are the final steps for reaching Bose-Einstein condensation. The set-up is designed to host experiments including variable geometry optical lattices, and includes the possibility to align laser beams with high angular precision for this purpose. The breakdown of Bloch waves in a Bose-Einstein condensate is studied, attributed to the effect of energetic and dynamical instability. This experimental study is performed using a Bose-Einstein condensate in a moving one-dimensional optical lattice at LENS, Florence Italy. The optical lattice parameters, and the thermal distribution of the atomic sample required to trigger the instabilities, are detected, and compared with a theoretical model developed in parallel with the experiments. In close connection with these one-dimensional lattice studies, an experimental survey to characterize regimes of superradiant Rayleigh scattering and Bragg scattering is presented. Tunneling properties of repulsively bound atom pairs in double well potentials are characterized in an experiment at Johannes Gutenberg University, Mainz Germany. A three-dimensional optical lattice, producing an array of double wells with tunable properties is let to interact with a Bose-Einstein condensate. Pairs of ultracold atoms are produced on one side in the double wells, and their tunneling behavior, dependent on potential barrier and repulsion properties, is studied. A theoretical study of the crossover between one- and two-dimensional systems has been performed. The simulations were made for a two-dimensional array of atoms, where the behavior for different tunneling probabilities and atom-atom repulsion strengths was studied. Scaling relations for systems of variable sizes have been examined in detail, and numerical values for the involved variables have been found.

Jan 1, 20080 citations