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

Dave Boers·Christoph Weiss·Martin Holthaus
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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.

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Dave Boers, Christoph Weiss, Martin Holthaus. 2004-07-23. Bogoliubov speed of sound for a dilute Bose-Einstein condensate in a 3d optical lattice. https://doi.org/10.1209/epl%2Fi2004-10140-7

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