All optical formation of a Bose Einstein condensate

Jessica Butcher, Leif Humbert, Erik van Ooijen +4 more

Yoshiro Takahashi

We have achieved Bose-Einstein condensation of rubidium (87Rb) and ytterbium (174Yb) atoms by optical trapping method. After collecting the atoms in the magneto-optical trap, we have performed evaporative cooling for the atoms in the optical trap. The Time-Of-Flight signals clearly showed the anisotropic expansion of the atom cloud, which is the evidence of the formation of the condensates. Along with these our works, we review the recent experiments on Bose-Einstein condensation with optical trapping method.

Andrés Ulibarrena

L. Fallani, C. Fort, M. Inguscio

David R. Scherer

An apparatus for producing atomic-gas Bose-Einstein condensates (BECs) of 87-Rb atoms is described. The apparatus produces 87-Rb BECs in a dual-chamber vacuum system that incorporates magnetic transport of trapped atoms from the magneto-optical trapping cell to the BEC production cell via the operation of a series of overlapping magnet coils. The design, construction, and operation of the apparatus are described in detail. The apparatus is used to study the creation of quantized vortices in BECs by the merging and interference of multiple trapped condensates. In this experiment, a single harmonic potential well is partitioned into three sections by an optical barrier, enabling the simultaneous formation of three independent, uncorrelated BECs. The BECs may either merge together during their growth, or, for high-energy barriers, the BECs can be merged together by barrier removal after their formation. Either process may instigate vortex formation in the resulting BEC, depending on the initially indeterminate relative phases of the condensates and the merging rate.

Evgeny S. Sedov, M. V. Charukhchyan, Sergei M Arakelyan +3 more

We consider the problem of formation of small amplitude spatially localized oscillatory structures for atomic Bose-Einstein condensate (BEC) confined in two and three dimensional optical lattices (OL's), respectively. By using kp-method we have demonstrated mapping of the initial Gross-Pitaevskii equation on nonlinear Klein-Gordon equations. Formation of breather-like oscillating localized states - atomic oscillons - have been predicted in this case.