Landau levels, Bardeen polynomials, and Fermi arcs in Weyl semimetals: Lattice-based approach to the chiral anomaly
Landau levels, Bardeen polynomials, and Fermi arcs in Weyl semimetals: Lattice-based approach to the chiral anomaly
复制标题
DOI：
10.1103/physrevb.99.140201
复制
发表时间：
2018-07
影响因子：
3.7
通讯作者：
Jan Behrends;S. Roy;M. Kolodrubetz;J. Bardarson;A. Grushin
中科院分区：
文献类型：
--
作者：
Jan Behrends;S. Roy;M. Kolodrubetz;J. Bardarson;A. Grushin
实现Weyl费米子的凝聚态系统表现出惊人的现象学，源于它们的拓扑保护表面态以及电磁场引起的手性异常。最近，预测非均匀应变或磁化会导致手性电场$\mathbf{E}_5$和磁场$\mathbf{B}_5$，这用附加项修正和丰富了手性异常。在这项工作中，我们开发了一种基于格的方法来描述手性异常，它涉及朗道和伪朗道水平，并在平等的基础上处理所有自然包含费米弧线的异常项。我们通过i)物理解释费米弧在协变（费米能级）对异常的贡献中很大程度上被忽视的作用，以及ii)重新访问异常中$\mathbf{E}_5\cdot\mathbf{B}_5$项的协变和一致（完整带）贡献之间的$1/3$差异因素来说明其潜力。我们的框架为分析现实晶格模型中的异常提供了一个通用工具，也为理解应变和磁化非均匀Weyl半金属提供了一个简单的物理直觉来源。
Condensed matter systems realizing Weyl fermions exhibit striking phenomenology deriving from their topologically protected surface states as well as chiral anomalies induced by electromagnetic fields. More recently, inhomogeneous strain or magnetization were predicted to result in chiral electric $\mathbf{E}_5$ and magnetic $\mathbf{B}_5$ fields, which modify and enrich the chiral anomaly with additional terms. In this work we develop a lattice-based approach to describe the chiral anomaly, which involves Landau and pseudo-Landau levels and treats all anomalous terms on equal footing naturally incorporating Fermi arcs. We exemplify its potential by i) physically interpreting the largely overlooked role of Fermi arcs in the covariant (Fermi level) contribution to the anomaly and ii) revisiting the factor of $1/3$ different between the covariant and consistent (complete band) contributions to the $\mathbf{E}_5\cdot\mathbf{B}_5$ term in the anomaly. Our framework provides a versatile tool for the analysis of anomalies in realistic lattice models as well as a source of simple physical intuition for understanding strained and magnetized inhomogeneous Weyl semimetals.