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Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover

Hui Hu·A. Minguzzi·Xia-Ji Liu·M. P. Tosi
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Abstract

We evaluate the frequencies of collective modes and the anisotropic expansion rate of a harmonically trapped Fermi superfluid at varying coupling strengths across a Feshbach resonance driving a BCS-BEC crossover. The equations of motion for the superfluid are obtained from a microscopic mean-field expression for the compressibility and are solved within a scaling ansatz. Our results confirm non-monotonic behavior in the crossover region and are in quantitative agreement with current measurements of the transverse breathing mode by Kinast {\it et al.} [Phys. Rev. Lett. {\bf 92}, 150402 (2004)] and of the axial breathing mode by Bartenstein {\it et al.} [Phys. Rev. Lett. {\bf 92}, 203201 (2004)].

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Hui Hu, A. Minguzzi, Xia-Ji Liu, M. P. Tosi. 2004-10-26. Collective modes and ballistic expansion of a Fermi gas in the BCS-BEC crossover. https://doi.org/10.1103/physrevlett.93.190403

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