Frankfurt 2006 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

Q: Quantenoptik und Photonik

Q 14: Quantengase III

Q 14.2: Talk

Monday, March 13, 2006, 17:15–17:30, HVI

Coherence in two dimensional Bose-Einstein condensates — •Peter Krüger, Baptiste Battelier, Marc Cheneau, Sabine Stock, Zoran Hadzibabic, and Jean Dalibard — Laboratoire Kastler Brossel, Ecole Normale Supérieure, 75005 Paris, France

We explore both isotropic and elongated quasi-two dimensional Bose-Einstein condensates held in a combination of optical and magnetic potentials. We have observed phase defects in quasi-2D Bose-Einstein condensates close to the condensation temperature. Either a single or several equally spaced condensates are produced by selectively evaporating the sites of a 1D optical lattice. When several clouds are released from the lattice and allowed to overlap, dislocation lines in the interference patterns reveal nontrivial phase defects.

The phase distribution in elongated 2D condensates is measured as a function of temperature by imaging interference patterns along the direction perpendicular to the long axis of the flat clouds. This allows to determine how the coherence properties of the gas depend on temperature.