Landau damping of Bogoliubov excitations in two- and three-dimensional optical lattices at finite temperatures

Journal Article · Tue Nov 15 04:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.72.0· OSTI ID:20786567

Tsuchiya, Shunji ^[1]; Griffin, Allan ^[1]

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1. Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7 (Canada)

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 n{sup c0}(T) 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 {sup 4}He. This leads to the disappearance of all damping processes in a D-dimensional simple cubic optical lattice when Un{sup c0}{>=}6DJ, where U is the on-site interaction, and J is the hopping matrix element.

• OSTI ID: 20786567
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 5 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
APPROXIMATIONS
ATOMS
BOSE-EINSTEIN CONDENSATION
EXCITATION
HELIUM 4
HUBBARD MODEL
LANDAU DAMPING
MATRIX ELEMENTS
ONE-DIMENSIONAL CALCULATIONS
PHONONS
SUPERFLUIDITY
TEMPERATURE DEPENDENCE
THREE-DIMENSIONAL CALCULATIONS