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arXiv · 0912.2849

Density excitations of a harmonically trapped ideal gas

Jai Carol Cruz·C. N. Kumar·K. N. Pathak·J. Bosse
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Abstract

The dynamic structure factor of a harmonically trapped Bose gas has been calculated well above the Bose-Einstein condensation temperature by treating the gas cloud as a canonical ensemble of noninteracting classical particles. The static structure factor is found to vanish as wavenumber squared in the long-wavelength limit. We also incorporate a relaxation mechanism phenomenologically by including a stochastic friction force to study the dynamic structure factor. A significant temperature dependence of the density-fluctuation spectra is found. The Debye-Waller factor has been calculated for the trapped thermal cloud as function of wavenumber and of particle number. A substantial difference is found between clouds of small and large particle number.

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Jai Carol Cruz, C. N. Kumar, K. N. Pathak, J. Bosse. 2009-12-15. Density excitations of a harmonically trapped ideal gas. https://doi.org/10.1007/s12043-010-0010-2

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