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arXiv 0801.0592cond-mat.str-el
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开边界条件下系统的Drude权

Drude weight in systems with open boundary conditions

Marcos Rigol, B. Sriram Shastry

摘要:

对于有限系统,电导率的实部通常被分解为零频率δ峰和有限频率正则部分之和。在具有周期性边界条件的研究中,Drude权重,即,零频率δ峰的权重对于可积系统即使在非常高的温度下也是非零的,而对于一般(不可积)系统它为零。奇异地,对于具有开边界条件的系统,可以证明,对于任何有限系统,零频率δ峰值的系数都是零,而不管其可积性如何。为了使Drude重量成为一个有意义的量,两种边界条件在热力学极限下应该产生相同的结果。我们揭示了这些问题,通过使用分析和数值方法。

英文摘要:

For finite systems, the real part of the conductivity is usually decomposed as the sum of a zero frequency delta peak and a finite frequency regular part. In studies with periodic boundary conditions, the Drude weight, i.e., the weight of the zero frequency delta peak, is found to be nonzero for integrable systems, even at very high temperatures, whereas it vanishes for generic (nonintegrable) systems. Paradoxically, for systems with open boundary conditions, it can be shown that the coefficient of the zero frequency delta peak is identically zero for any finite system, regardless of its integrability. In order for the Drude weight to be a thermodynamically meaningful quantity, both kinds of boundary conditions should produce the same answer in the thermodynamic limit. We shed light on these issues by using analytical and numerical methods.

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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