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arXiv 2007.11852cond-mat.mes-hallhep-th
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量子反常霍尔绝缘体中宇称反常的温度和化学势依赖性

Temperature and Chemical Potential Dependence of the Parity Anomaly in Quantum Anomalous Hall Insulators

C. Tutschku, F. S. Nogueira, C. Northe, J. van den Brink, E. M. Hankiewicz

摘要:

二维量子反常霍尔绝缘体如(Hg,Mn)Te量子阱或磁掺杂(Bi,Sb)Te薄膜的低能物理可以有效地用两个包含Dirac的Chern绝缘体以及动量相关的质量项来描述。这些陈氏绝缘体中的每一个都与平面量子电动力学的宇称异常直接相关。在这项工作中,我们分析了在2+1时空维的化学势和面外磁场的影响下,一个单一的陈氏绝缘体的有限温度霍尔电导率。在零磁场下,这种非耗散输运系数源于平面量子电动力学的宇称反常。我们表明,宇称异常本身是不重整化的有限温度效应。然而,它在陈式绝缘体的有效作用中引入了两个不同物理来源的项,这与霍尔电导率成正比。第一项与温度和化学势无关,并且仅编码内在拓扑响应。第二项规定了传导和价带态的非拓扑热响应。特别是,我们表明,陈绝缘体的相对论质量抵消有限的温度效应,而其非相对论质量增强这些修正。此外,我们扩展我们的分析,有限的磁场和相关的陈绝缘体的热响应的光谱不对称性,这是一个衡量的宇称异常的轨道场。

英文摘要:

The low-energy physics of two-dimensional Quantum Anomalous Hall insulators like (Hg,Mn)Te quantum wells or magnetically doped (Bi,Sb)Te thin films can be effectively described by two Chern insulators, including a Dirac, as well as a momentum-dependent mass term. Each of those Chern insulators is directly related to the parity anomaly of planar quantum electrodynamics. In this work, we analyze the finite temperature Hall conductivity of a single Chern insulator in 2+1 space-time dimensions under the influence of a chemical potential and an out-of-plane magnetic field. At zero magnetic field, this non-dissipative transport coefficient originates from the parity anomaly of planar quantum electrodynamics. We show that the parity anomaly itself is not renormalized by finite temperature effects. However, it induces two terms of different physical origin in the effective action of a Chern insulator, which is proportional to the Hall conductivity. The first term is temperature and chemical potential independent, and solely encodes the intrinsic topological response. The second term specifies the non-topological thermal response of conduction and valence band states. In particular, we show that the relativistic mass of a Chern insulator counteracts finite temperature effects, whereas its non-relativistic mass enhances these corrections. Moreover, we extend our analysis to finite magnetic fields and relate the thermal response of a Chern insulator therein to the spectral asymmetry, which is a measure of the parity anomaly in orbital fields.

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