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Title

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

Author(s)

Hu, Hui;  Minguzzi, A.;  Liu, Xia-Ji;  Tosi, M. P.

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 nonmonotonic behavior in the crossover region and are in quantitative agreement with current measurements of the transverse breathing mode by Kinast et al. [Phys. Rev. Lett. 92, 150402 (2004)] and of the axial breathing mode by Bartenstein et al. [Phys. Rev. Lett. 92, 203201 (2004)].

Publication type

Journal article

Source

Physical Review Letters, Vol. 93, no. 19 (Nov 2004), article no. 190403

Publication year

2004

FOR Code(s)

01 Mathematical Sciences;  02 Physical Sciences;  09 Engineering

Keyword(s)

Approximation theory;  Ballistic expansion;  Bardeen-Cooper-Schrieffer superfluid;  BEC-BCS crossovers;  Bose-Einstein condensation;  Collective modes;  Compressibility;  Equations of motion;  Fermi gases;  Fermi level;  Gases;  Hydrodynamics;  LDA;  Local density approximation;  Natural frequencies;  Parameter estimation;  Resonance

Publisher

American Physical Society

ISSN

0031-9007

Publisher URL

http://dx.doi.org/10.1103/PhysRevLett.93.190403

Copyright

Copyright © 2004 The American Physical Society. The accepted manuscript of the paper is reproduced here for noncommerical purposes only in accordance with the copyright policy of the publisher.

Full text

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