中国物理B ›› 2013, Vol. 22 ›› Issue (8): 80308-080308.doi: 10.1088/1674-1056/22/8/080308

• GENERAL • 上一篇    下一篇

Excitation spectrum and structure factor of a two-component Bose-Einstein condensate in different hyperfine states

韩玉峰a, 陈良b, 刘厚通a, 黄仙山a   

  1. a Department of Mathematics and Physics, Anhui University of Technology, Ma'anshan 243032, China;
    b Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2012-09-26 修回日期:2013-01-22 出版日期:2013-06-27 发布日期:2013-06-27
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10974189, 10675114, 10675115, and 41075027) and the Natural Science College Key Projects of Anhui Province, China (Grant No. KJ2011A040).

Excitation spectrum and structure factor of a two-component Bose-Einstein condensate in different hyperfine states

Han Yu-Feng (韩玉峰)a, Chen Liang (陈良)b, Liu Hou-Tong (刘厚通)a, Huang Xian-Shan (黄仙山)a   

  1. a Department of Mathematics and Physics, Anhui University of Technology, Ma'anshan 243032, China;
    b Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
  • Received:2012-09-26 Revised:2013-01-22 Online:2013-06-27 Published:2013-06-27
  • Contact: Han Yu-Feng E-mail:hipeak@ahut.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 10974189, 10675114, 10675115, and 41075027) and the Natural Science College Key Projects of Anhui Province, China (Grant No. KJ2011A040).

摘要: The elementary excitation spectrum of a two-component Bose-Einstein condensate in different hyperfine states is obtained by Green's function method. It is found to have two branches. In the long wave-length limit, the two branches of the excitation spectrum are reduced to one phonon excitation and one single-particle excitation. The single-particle one has an energy gap. When the energy gap exists, we study the Landau critical velocity and the depletion of the condensate. With the obtained Green's functions, we calculate the structure factor of a two-component condensate. It is found that the static structure factor comprises only the branch of the phonon excitation and the single-particle excitation makes no contribution to the structure factor.

关键词: elementary excitation, Bose-Einstein condensate, structure factor

Abstract: The elementary excitation spectrum of a two-component Bose-Einstein condensate in different hyperfine states is obtained by Green's function method. It is found to have two branches. In the long wave-length limit, the two branches of the excitation spectrum are reduced to one phonon excitation and one single-particle excitation. The single-particle one has an energy gap. When the energy gap exists, we study the Landau critical velocity and the depletion of the condensate. With the obtained Green's functions, we calculate the structure factor of a two-component condensate. It is found that the static structure factor comprises only the branch of the phonon excitation and the single-particle excitation makes no contribution to the structure factor.

Key words: elementary excitation, Bose-Einstein condensate, structure factor

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

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