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arXiv 0704.0692cond-mat.supr-concond-mat.str-el
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超导哈伯德模型双带平均场格林函数的严格推导

Rigorous derivation of the mean field Green functions of the two-band Hubbard model of superconductivity

Gh. Adam, S. Adam

摘要:

用格林函数运动方程技术求解铜酸盐高温超导的有效双带哈伯德模型[N.M. Plakida等人,Phys. Rev. B,v. 51,16599(1995); JETP,v. 97,331(2003)]依赖于Hubbard算子(HO)代数。我们表明,如果我们考虑平移和自旋反转的不变性,HO代数的结果在几个特定的关联函数的不变性。使用这些属性允许严格的推导和简化的频率矩阵(FM)和广义平均场近似(GMFA)的格林函数(GF)的模型的表达式。对于进入FM和GMFA-GF的正常单重态跳跃和异常交换配对关联函数,描述了基于指数小量的识别和消除的近似过程。它保证了GMFA-GF表达式的相关阶的降低。

英文摘要:

The Green function (GF) equation of motion technique for solving the effective two-band Hubbard model of high-T_c superconductivity in cuprates [N.M. Plakida et al., Phys. Rev. B, v. 51, 16599 (1995); JETP, v. 97, 331 (2003)] rests on the Hubbard operator (HO) algebra. We show that, if we take into account the invariance to translations and spin reversal, the HO algebra results in invariance properties of several specific correlation functions. The use of these properties allows rigorous derivation and simplification of the expressions of the frequency matrix (FM) and of the generalized mean field approximation (GMFA) Green functions (GFs) of the model. For the normal singlet hopping and anomalous exchange pairing correlation functions which enter the FM and GMFA-GFs, an approximation procedure based on the identification and elimination of exponentially small quantities is described. It secures the reduction of the correlation order to GMFA-GF expressions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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