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TT: Fachverband Tiefe Temperaturen
TT 37: MLT: Poster Session
TT 37.11: Poster
Thursday, March 25, 2010, 14:00–18:00, Poster A
Local mean-field theory for quantum phase transitions in disordered Bose-Hubbard systems — •Astrid Elisa Niederle and Heiko Rieger — Theoretical Physics, Saarland University, D-66041 Saarbrücken
The Bose-Hubbard model represents a theoretical approach to study Bose-Einstein condensates in diverse kinds of optical lattices. We focus on the influence of disorder in these systems and especially the phase transitions in dependence of the system parameters and study the properties of a Bose-Einstein condensate in an optical trap with an equally distributed disorder in the on-site energies. We develop a local mean-field approach to investigate the transitions between the three competing phases (superfluid, Mott insulator, Bose glass), which can be observed in dependence of the system parameters. Beside the global changes of the phase diagram in dependence of the geometry, finite size effects are discussed.