Hannover 2020 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 9: Quantum gases (Bosons) I
Q 9.4: Talk
Monday, March 9, 2020, 15:00–15:15, e214
Scaling analysis of localization effects in the disordered two-dimensional Bose-Hubbard-model — •Andreas Geißler1,2 and Guido Pupillo1,3 — 1ISIS, University of Strasbourg, Strasbourg, France — 2Institut für Theoretische Physik, Goethe-Universität, Frankfurt am Main, Germany — 3IPCMS, University of Strasbourg, Strasbourg, France
Recent experiments have shown signatures of many-body localization (MBL) in the disordered Bose-Hubbard model in one and two dimensional ultra cold atomic lattice gases [1] as well as the related superfluid to Bose-glass transition in three dimensions [2]. A proper theoretical understanding of the MBL phenomenon depends on knowledge about the full eigenstate spectrum. Therefore, exact numerical studies have been limited to small system sizes. In contrast, the Bose-glass phase can already be understood via the ground state. So, by applying the fluctuation operator expansion method [3] to obtain beyond mean-field insight into the full fluctuation spectrum, we have performed a scaling analysis of both phenomena within a single framework. With the collection of obtained critical points, we are able to map out a phase diagram showing no direct superfluid to fully localized transition due to the intermediate Bose-glass phase. We further discuss the scaling of correlations for various quenches.
[1] C. D'Errico et al., PRL 113, 095301 (2014); J.-y. Choi et al., Science 352, 1547 (2016)
[2] C. Meldgin et al., Nature Physics 12, 646 (2016)
[3] A. Geissler et al., PRA 98, 063635 (2018)