Landau damping of Bogoliubov excitations in two- and three-dimensional optical lattices at finite temperatures
- 18 November 2005
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review A
- Vol. 72 (5), 053621
- https://doi.org/10.1103/physreva.72.053621
Abstract
We study the Landau damping of Bogoliubov excitations in two- and three-dimensional optical lattices at finite temperatures, extending our recent work on one-dimensional (1D) optical lattices. We use a Bose-Hubbard tight-binding model and the Popov approximation to calculate the temperature dependence of the number of condensate atoms in each lattice well. As with 1D optical lattices, damping only occurs if the Bogoliubov excitations exhibit anomalous dispersion (i.e., the excitation energy bends upward at low momentum), analogous to the case of phonons in superfluid . This leads to the disappearance of all damping processes in a -dimensional simple cubic optical lattice when , where is the on-site interaction, and is the hopping matrix element.
Keywords
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