2005/06/04 by A. Trombettoni, A. Smerzi, P. Sodano
Physics and Astronomy · #cond-mat.stat-mech
published as Laser Physics 15, 669 (2005)
arxiv created 2005/06/04 · arxiv updated 2009/12/01
We discuss the finite-temperature properties of Bose-Einstein condensates loaded on a 2D optical lattice. In an experimentally attainable range of parameters the system is described by the XY model, which undergoes a Berezinskii-Kosterlitz-Thouless (BKT) transition driven by the vortex pair unbinding. The interference pattern of the expanding condensates provides the experimental signature of the BKT transition: near the critical temperature, the k=0 component of the momentum distribution sharply decreases.