中国物理B ›› 2009, Vol. 18 ›› Issue (2): 715-725.doi: 10.1088/1674-1056/18/2/051

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

The quantum pressure correction to the excitation spectrum of the trapped superfluid Fermi gases in a BEC-BCS crossover

董行, 马永利   

  1. Department of Physics, Fudan University, Shanghai 200433, China
  • 收稿日期:2008-08-06 修回日期:2008-09-05 出版日期:2009-02-20 发布日期:2009-02-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574028, 10775032 and J0730310).

The quantum pressure correction to the excitation spectrum of the trapped superfluid Fermi gases in a BEC-BCS crossover

Dong Hang(董行) and Ma Yong-Li(马永利)†   

  1. Department of Physics, Fudan University, Shanghai 200433, China
  • Received:2008-08-06 Revised:2008-09-05 Online:2009-02-20 Published:2009-02-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574028, 10775032 and J0730310).

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摘要： Using quantum hydrodynamic approaches, we study the quantum pressure correction to the collective excitation spectrum of the interacting trapped superfluid Fermi gases in the BEC-BCS crossover. Based on a phenomenological equation of state, we derive hydrodynamic equations of the system in the whole BEC-BCS crossover regime. Beyond the Thomas--Fermi approximation, expressions of the frequency corrections of collective modes for both spherical and axial symmetric traps excited in the BEC-BCS crossover are given explicitly. The corrections of the eigenfrequencies due to the quantum pressure and their dependence on the inverse interaction strength, anisotropic parameter and particle numbers of the condensate are discussed in detail.

Abstract: Using quantum hydrodynamic approaches, we study the quantum pressure correction to the collective excitation spectrum of the interacting trapped superfluid Fermi gases in the BEC-BCS crossover. Based on a phenomenological equation of state, we derive hydrodynamic equations of the system in the whole BEC-BCS crossover regime. Beyond the Thomas--Fermi approximation, expressions of the frequency corrections of collective modes for both spherical and axial symmetric traps excited in the BEC-BCS crossover are given explicitly. The corrections of the eigenfrequencies due to the quantum pressure and their dependence on the inverse interaction strength, anisotropic parameter and particle numbers of the condensate are discussed in detail.

Key words: BEC-BCS crossover, hydrodynamic approaches, perturbation method

中图分类号:  (Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow)

  • 03.75.Kk
03.75.Ss (Degenerate Fermi gases) 37.10.De (Atom cooling methods) 05.30.Fk (Fermion systems and electron gas)