中国物理B ›› 2011, Vol. 20 ›› Issue (7): 70307-070307.doi: 10.1088/1674-1056/20/7/070307

• GENERAL • 上一篇    下一篇

Landau damping of collective mode in a quasi-two-dimensional repulsive Bose–Einstein condensate

马晓栋, 杨占金, 路俊哲, 魏蔚   

  1. College of Physics and Electronic Engineering, Xinjiang Normal University, Urumchi 830054, China
  • 收稿日期:2011-01-13 修回日期:2011-02-15 出版日期:2011-07-15 发布日期:2011-07-15

Landau damping of collective mode in a quasi-two-dimensional repulsive Bose–Einstein condensate

Ma Xiao-Dong(马晓栋), Yang Zhan-Jin(杨占金), Lu Jun-Zhe(路俊哲), and Wei Wei(魏蔚)   

  1. College of Physics and Electronic Engineering, Xinjiang Normal University, Urumchi 830054, China
  • Received:2011-01-13 Revised:2011-02-15 Online:2011-07-15 Published:2011-07-15

摘要: We investigate the Landau damping of the collective mode in a quasi-two-dimension repulsive Bose—Einstein condensate by using the self-consistent time-dependent Hatree—Fock—Bogoliubov approximation and a complete and orthogonal eigenfunction set for the elementary excitation of the system. We calculate the three-mode coupling matrix element between the collective mode and the thermal excited quasi-particles and the Landau damping rate of the collective mode. We discuss the dependence of the Landau damping on temperature, on atom number in the condensate, on transverse trapping frequency and on the length of the condensate. The energy width of the collective mode is taken into account in our calculation. With little approximation, our theoretic calculation results agree well with the experimental ones and are helpful for deducing the damping mechanics and the inter-particle interaction.

Abstract: We investigate the Landau damping of the collective mode in a quasi-two-dimension repulsive Bose—Einstein condensate by using the self-consistent time-dependent Hatree—Fock—Bogoliubov approximation and a complete and orthogonal eigenfunction set for the elementary excitation of the system. We calculate the three-mode coupling matrix element between the collective mode and the thermal excited quasi-particles and the Landau damping rate of the collective mode. We discuss the dependence of the Landau damping on temperature, on atom number in the condensate, on transverse trapping frequency and on the length of the condensate. The energy width of the collective mode is taken into account in our calculation. With little approximation, our theoretic calculation results agree well with the experimental ones and are helpful for deducing the damping mechanics and the inter-particle interaction.

Key words: Bose—Einstein condensate, Landau damping, Hatree—Fock—Bogoliubov approximation, energy level width

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

  • 03.75.Kk
05.30.Jp (Boson systems) 67.10.Db (Fermion degeneracy)