Seminar
Tuesday, 23 February, 2010
Group Seminar MPQ: The equilibrium state of a trapped two-dimensional Bose gas
Tuesday, 23.02.2010 10 a.m. (s.t.) in Herbert-Walther-lecture room, MPQ Garching
Dr. Kenneth J. Günter, votex group (Jean Dalibard), Laboratoire Kastler Brossel http://www.lkb.ens.fr/
Low-dimensional quantum systems exhibit enhanced thermal and quantum fluctuations that make 'beyond mean-field' effects more apparent than in three dimensions. A feature specific to the uniform two-dimensional Bose gas, is the approximate scale invariance of its equation of state. In my talk I will present our measurements of equilibrium density profiles of a trapped 2D Bose gas, which can be related to the equation of state of the homogeneous system using the local density approximation. In-situ measurements show significant discrepancies with respect to quantum Monte-Carlo simulations, which we attribute to a reduced detection efficiency at high atomic densities. However, exploiting the self-similarity of the density distribution after a two-dimensional expansion of the cloud, we find good agreement with theory.