Bogoliubov speed of sound for a dilute Bose-Einstein condensate in a 3d optical lattice

Abstract

We point out that the velocity of propagation of sound wavepackets in a Bose-Einstein condensate filling a three-dimensional cubic optical lattice undergoes a maximum with increasing lattice depth. For a realistic choice of parameters, the maximum sound velocity in a lattice condensate can exceed the sound velocity in a homogeneous condensate with the same average density by 30%. The maximum falls into the superfluid regime, and should be observable under currently achievable laboratory conditions.

6 pages, 2 figures, accepted for publication in Europhys. Lett. http://www.epletters.ch/

References in corpus (2)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Bose-Einstein condensates in 1D optical lattices: compressibility, Bloch bands and elementary excitations

Cited by in corpus (6)

• Sweeping from the superfluid to Mott phase in the Bose-Hubbard model
• Bogoliubov theory of quantum correlations in the time-dependent Bose-Hubbard model
• Tunneling-induced damping of phase coherence revivals in deep optical lattices
• Exact nonlinear Bloch-state solutions for Bose-Einstein condensates in a periodic array of quantum wells
• Probing Sound Speed of an Optically-Trapped Bose Gas with Periodically Modulated Interactions by Bragg Spectroscopy
• Unusual behavior of sound velocity of a Bose gas in an optical superlattice at quasi-one-dimension