Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 17: Quantengase (Bosonische Gitter I)
Q 17.8: Vortrag
Dienstag, 20. März 2007, 12:15–12:30, 6J
Visibility of Atomic Cloud Released from Optical Lattice — •Alexander Hoffmann1, Konstantin Krutitsky2, and Axel Pelster2 — 1Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany — 2Fachbereich Physik, Universität Duisburg-Essen, Lotharstraße 1, 47048 Duisburg, Germany
We present an analytical calculation for the interference pattern of an atomic cloud which expands from an optical lattice. To this end we work out a variational approach which considers quantum fluctuations beyond the mean-field level for finite temperatures. The resulting visibility of the interference pattern indicates both short-range and long-range coherence in the Mott insulator and the superfluid regime, respectively. Furthermore, we account for inhomogeneity effects, which arise from an overall harmonic trap.