Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 21: Solids at Low Temperature - Poster Session

TT 21.5: Poster

Mittwoch, 28. März 2007, 14:00–17:45, Poster A

Extended mean-field theory for disordered bosons in optical lattices — •Ulf Bissbort and Walter Hofstetter — Institut für Theoretische Physik, J.W. Goethe-Universität, D-60438 Frankfurt, Germany

We consider bosons in disordered optical lattices at zero temperature for various disorder realizations in a mean-field approximation of the Hubbard model. Hitherto the problem of random on-site disorder was tackled using modifications of the usual single site mean-field theory or spatially resolved methods, which use a limited number of sites. We propose a new extended mean-field theory, which takes dimensional effects into account and is applicable in the thermodynamic limit. Within this method we suggest criteria to distinguish between the Mott insulating, the Bose glass and the superfluid phases. Results are presented for the ground-state phase diagram and experimental accessibility is discussed.