Seminar
Tuesday, 24 November, 2009
Group seminar MPQ: Second-order correlations of expanding Bose gases across the BEC phase transition
Tuesday, 24.11.2009 10 a.m. (s.t.) in Herbert-Walther-lecture room, MPQ Garching
Dr. Aurélien Perrin, Quantumoptics Group, Vienna University of Technology
We present a new type of single-atom-sensitive detector based on the fluorescence of atoms passing through a resonant "sheet of light" [1]. The detector yields single atom sensitivity (>60%) together with a spatial resolution of 10 μm. Using this scheme we can study second-order correlations of ultracold atom systems in time of flight. Specifically, we investigate two-particle correlations across the BEC phase transition threshold for 3D and quasi-1D condensates. Above the threshold we observe the bunching effect of thermal bosons. Below the threshold we show that the shape of the second-order correlation function acquires an oscillatory behaviour that can be related to near-field diffraction effects. For quasi-1D condensates, it is possible to compare our results to recent theoretical models [2].
Bibliography :
[1] R. Bücker et al, http://arxiv.org/abs/0907.0674
[2] A. Imambekov et al, PRA 80, 033604 (2009)