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Damping of condensate collective modes due to equilibration with the non-condensate

J. E. Williams·A. Griffin
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Abstract

We consider the damping of condensate collective modes at finite temperatures arising from lack of equilibrium between the condensate and the non-condensate atoms, an effect that is ignored in the usual discussion of the collisionless region. As a first approximation, we ignore the dynamics of the thermal cloud. Our calculations should be applicable to collective modes of the condensate which are oscillating out-of-phase with the thermal cloud. We obtain a generalized Stringari equation of motion for the condensate at finite temperatures, which includes a damping term associated with the fact that the condensate is not in diffusive equilibrium with the static thermal cloud. This inter-component collisional damping of the condensate modes is comparable in magnitude to the Landau damping considered in the recent literature.

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J. E. Williams, A. Griffin. 2000-10-04. Damping of condensate collective modes due to equilibration with the non-condensate. https://doi.org/10.1103/physreva.63.023612

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