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

被引:0
作者
Han Yu-Feng [1 ]
Chen Liang [2 ]
Liu Hou-Tong [1 ]
Huang Xian-Shan [1 ]
机构
[1] Anhui Univ Technol, Dept Math & Phys, Maanshan 243032, Peoples R China
[2] Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Peoples R China
基金
中国国家自然科学基金;
关键词
elementary excitation; Bose-Einstein condensate; structure factor; GROUND-STATE; ENTANGLEMENT; SYSTEM; GAS;
D O I
10.1088/1674-1056/22/8/080308
中图分类号
O4 [物理学];
学科分类号
0702 ;
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.
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页数:8
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