Hannover 2010 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 23: Poster II

A 23.31: Poster

Donnerstag, 11. März 2010, 16:30–19:00, Lichthof

Stochastic Mean-Field Theory for the Bose-Hubbard Model with Speckle Disorder — •Ulf Bissbort¹, Ronny Thomale², and Walter Hofstetter¹ — ¹Institut für Theoretische Physik, Goethe Universität Frankfurt — ²Department of Physics Princeton University

Using the recently developed stochastic mean-field theory (SMFT) for the disordered Bose-Hubbard model [1], we investigate the phase diagram of interacting bosons with experimentally realistic speckle disorder [2]. In comparison to prototypical box disorder, we find deviations in the phase diagram at low temperature. At fixed density and sufficiently low temperature, we identify parameter regimes at which disorder-induced superfluidity and multiple reentrant behavior is predicted. Our results at finite temperature explain the absence of this phenomenon in recent experiments. In addition to pure on-site disorder, we furthermore include uncorrelated off-diagonal disorder in the hopping energies within the SMFT formalism. To account for effects of the trapping potential and allow for a quantitative comparison with experiments, we also present results of a SMFT + LDA calculation.

[1] U. Bissbort and W. Hofstetter, EPL 86 50007 (2009).

[2] M. White et al., Phys. Rev. Lett. 102, 055301 (2009).