Nonequivalent operator representations for Bose-condensed systems
Nonequivalent operator representations for Bose-condensed systems
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Bose 压缩系统的非等效运算符表示
DOI：
10.1134/s1054660x06030145
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发表时间：
2006
期刊：
影响因子：
1.2
通讯作者：
V. Yukalov
中科院分区：
文献类型：
--
作者：
V. Yukalov
准确地考虑到与规范变换相关的非等价算子表示的存在的必要性进行了讨论。它表明，玻色系统中的玻色-爱因斯坦凝聚体的存在和没有它对应于不同的Fock空间，相互正交。场算子的复合表示构造允许玻色凝聚系统的自洽描述。从给定的哈密顿量导出运动方程，保证守恒律和热力学自洽性的有效性。同时，无论是对角化这个哈密顿量还是线性化场算符运动方程得到的粒子谱都没有间隙。凝聚存在的条件保证了光谱中不存在差距，而与所涉及的近似无关。所建议的自洽理论是既保守又无间隙的。
The necessity of accurately taking into account the existence of nonequivalent operator representations associated with canonical transformations is discussed. It is demonstrated that Bose systems in the presence of the Bose-Einstein condensate and without it correspond to different Fock spaces, orthogonal to each other. A composite representation for the field operators is constructed allowing for a self-consistent description of Bose-condensed systems. Equations of motion are derived from the given Hamiltonian, which guarantees the validity of conservation laws and thermodynamic self-consistency. At the same time, the particle spectrum obtained either from diagonalizing this Hamiltonian or from linearizing the field-operator equations of motion has no gap. The condition of the condensate existence assures the absence of the gap in the spectrum, irrespectively to the approximation involved. The suggested self-consistent theory is both conserving and gapless.
玻色-爱因斯坦凝聚态守恒无间隙平均场理论
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
富田憲一;那須奉一郎;T. Kita;山下博雅・北 孝文;近藤佳之;北 孝文;近藤佳之・北 孝文・水島健;近藤佳之・北 孝文・水島健;山下博雅;北 孝文;T. Kita
通讯作者：
T. Kita