Density excitations of a harmonically trapped ideal gas

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.

References in corpus (5)

• Probing Pair-Correlated Fermionic Atoms through Correlations in Atom Shot Noise
• Dynamical density-density correlations in the one-dimensional Bose gas
• Theory of coherent Bragg spectroscopy of a trapped Bose-Einstein condensate
• Dynamic structure factor of a Bose Einstein condensate in a 1D optical lattice
• Dielectric formalism and damping of collective modes in trapped Bose-Einstein condensed gases