Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 49: Quantum gases: Lattices I
Q 49.1: Talk
Thursday, March 20, 2014, 16:30–16:45, UDL HS2002
Hierarchy of correlations in the Bose-Hubbard model — •Patrick Navez1, Konstantin Krutitsky1, Friedemann Queisser2, and Ralf Schützhold1 — 1Universtät Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany — 2The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
We consider the Bose-Hubbard model in the (formal) limit of large coordination numbers Z and derive a hierarchy of correlations via the 1/Z-expansion. Truncating this expansion, we obtain a set of approximate equations governing the time-dependence of the on-site reduced density matrix and the correlations between two lattice sites (which can be far apart). In some cases, this set of equations can be solved analytically [1,2,3]. In the more general situation, a numerical solution yields the time-dependence of the correlations and provides an alternative to other techniques such as density-renormalization group (or matrix-product state) methods.
Ref: [1] Emergence of coherence in the Mott-superfluid quench of the Bose-Hubbard model, P. Navez, R. Schützhold, Phys. Rev. A, 82 063603 (2010); [2]Quasi-particle approach for general lattice Hamiltonians, P. Navez, F. Queisser, R. Schützhold, arXiv:1303.4112; [3]Equilibration versus (pre) thermalization in the Bose and Fermi Hubbard models, F. Queisser, K. Krutitsky, P. Navez, R. Schützhold, arXiv:1311.2212.