Transport properties of the one-dimensional Hubbard model at finite temperature
Transport properties of the one-dimensional Hubbard model at finite temperature
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有限温度下一维哈伯德模型的输运特性
DOI：
10.1103/physrevb.90.155104
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发表时间：
2014
影响因子：
3.7
通讯作者：
J. E. Moore
中科院分区：
文献类型：
--
作者：
C. Karrasch;D. M. Kennes;J. E. Moore
利用密度矩阵重整化群研究了一维Hubbard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电流的相关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。其次，我们计算了在小的可积性破坏次近邻相互作用（扩展的Hubbard模型）存在下的光电荷电导率。直流电导率是有限的，并且随着温度降低到低于差距而发散。因此，我们的研究结果表明，半填充，有间隙的哈伯德模型是一个正常的电荷导体在有限的温度。作为我们数值计算的一个试验平台，我们计算了可积XXZ自旋链的带隙相。
We study finite-temperature transport properties of the one-dimensional Hubbard model using the density matrix renormalization group. Our aim is twofold: 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 conductivityin the 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 test bed for our numerics, we computefor the integrable XXZ spin chain in its gapped phase.