Chiral response in lattice models of Weyl materials
Chiral response in lattice models of Weyl materials
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DOI：
10.1103/physrevb.96.125123
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发表时间：
2017-06
影响因子：
3.7
通讯作者：
E. V. Gorbar;V. A. Miransky;I. Shovkovy;P. Sukhachov
中科院分区：
文献类型：
--
作者：
E. V. Gorbar;V. A. Miransky;I. Shovkovy;P. Sukhachov
对于Weyl材料中电子态的一般晶格哈密顿量，我们解析地计算了背景电磁场和应变诱导伪电磁场中一阶的手性（或等效的谷）电荷和电流密度。我们发现伪电磁场引起的手性响应不受拓扑保护。虽然我们的计算定性地再现了异常手性霍尔效应，但电导率的实际结果取决于手性的定义以及晶格模型的参数。此外，对于围绕单个Weyl节点的分离良好的费米表面，磁场诱导的电流与线性化模型中手性分离效应的电流几乎完全一致，但当费米表面经历Lifshitz跃迁时，存在明显的偏差。一般来说，我们发现所有的手性反应系数在大的化学势下消失。
For a generic lattice Hamiltonian of the electron states in Weyl materials, we calculate analytically the chiral (or, equivalently, valley) charge and current densities in the first order in background electromagnetic and strain-induced pseudoelectromagnetic fields. We find that the chiral response induced by the pseudoelectromagnetic fields is not topologically protected. Although our calculations reproduce qualitatively the anomalous chiral Hall effect, the actual result for the conductivity depends on the definition of the chirality as well as on the parameters of the lattice model. In addition, while for the well- separated Fermi surfaces surrounding the individual Weyl nodes the current induced by the magnetic field coincides almost exactly with the current of the chiral separation effect in linearized models, there are clear deviations when the Fermi surfaces undergo the Lifshitz transition. In general, we find that all chiral response coefficients vanish at large chemical potential.