中国物理B ›› 2009, Vol. 18 ›› Issue (10): 4122-4129.doi: 10.1088/1674-1056/18/10/010

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Critical rotation of an anharmonically trapped Bose--Einstein condensate

马娟, 李志, 薛具奎   

  1. College of Physics and Electronics Engineering, Northwest Normal University, Lanzhou 730070, China
  • 收稿日期:2009-02-25 修回日期:2009-04-21 出版日期:2009-10-20 发布日期:2009-10-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10774120), the Natural Science Foundation of Gansu Province (Grant No 3ZS051-A25-013), and Natural Science Foundation of Northwest Normal University, China (Grant Nos NWNU-KJC

Critical rotation of an anharmonically trapped Bose--Einstein condensate

Ma Juan(马娟), Li Zhi(李志), and Xue Ju-Kui(薛具奎)   

  1. College of Physics and Electronics Engineering, Northwest Normal University, Lanzhou 730070, China
  • Received:2009-02-25 Revised:2009-04-21 Online:2009-10-20 Published:2009-10-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10774120), the Natural Science Foundation of Gansu Province (Grant No 3ZS051-A25-013), and Natural Science Foundation of Northwest Normal University, China (Grant Nos NWNU-KJC

摘要: We consider rotational motion of an interacting atomic Bose-Einstein condensate (BEC) with both two- and three-body interactions in a quadratic-plus-quartic and harmonic-plus-Gaussian trap. By using the variational method, the influence of the three-body interaction and the anharmonicity of the trap on the lowest energy surface mode excitation and the spontaneous shape deformation (responsible for the vortex formation) in a rotating BEC is discussed in detail. It is found that the repulsive three-body interaction helps the formation of the vortex and reduces the lowest energy surface mode frequency and the critical rotational frequency of the system. Moreover, the critical rotational frequency for the vortex formation in the harmonic-plus-Gaussian potential is lower than that in the quadratic-plus-quartic potential.

Abstract: We consider rotational motion of an interacting atomic Bose-Einstein condensate (BEC) with both two- and three-body interactions in a quadratic-plus-quartic and harmonic-plus-Gaussian trap. By using the variational method, the influence of the three-body interaction and the anharmonicity of the trap on the lowest energy surface mode excitation and the spontaneous shape deformation (responsible for the vortex formation) in a rotating BEC is discussed in detail. It is found that the repulsive three-body interaction helps the formation of the vortex and reduces the lowest energy surface mode frequency and the critical rotational frequency of the system. Moreover, the critical rotational frequency for the vortex formation in the harmonic-plus-Gaussian potential is lower than that in the quadratic-plus-quartic potential.

Key words: Bose--Einstein condensate, vortex, anharmonic potential

中图分类号:  (Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations)

  • 03.75.Lm
37.10.De (Atom cooling methods)