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arXiv 1408.1891cond-mat.str-el
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有限温度下一维哈伯德模型的输运性质

Transport properties of the one-dimensional Hubbard model at finite temperature

C. Karrasch, D. M. Kennes, J. E. Moore

摘要:

利用密度矩阵重整化群研究了一维哈伯德模型的有限温度输运性质。我们的目标是双重的:首先,我们计算的电荷和自旋流关联函数的可积模型在半填充。前者迅速衰减,这意味着相应的德鲁德权要么为零,要么非常小。第二,我们计算了存在小的可积性破坏次近邻相互作用(扩展的哈伯德模型)的光学电荷电导率σ(Ω)。直流电导率是有限的,并且随着温度降低到间隙以下而发散。因此,我们的结果表明,半填充,带隙的哈伯德模型是一个正常的电荷导体在有限的温度。作为我们的数值的测试平台,我们计算西格玛(欧米茄)的可积XXZ自旋链在其缺口阶段。

英文摘要:

We study finite-temperature transport properties of the one-dimensional Hubbard model using the density matrix renormalization group. Our aim is two-fold: First, we compute both the charge and the spin current correlation function of the integrable model at half filling. The former decays rapidly, implying that the corresponding Drude weight is either zero or very small. Second, we calculate the optical charge conductivity sigma(omega) in presence of small integrability-breaking next-nearest neighbor interactions (the extended Hubbard model). The DC conductivity is finite and diverges as the temperature is decreased below the gap. Our results thus suggest that the half-filled, gapped Hubbard model is a normal charge conductor at finite temperatures. As a testbed for our numerics, we compute sigma(omega) for the integrable XXZ spin chain in its gapped phase.

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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