Theory of Kerr and Faraday rotations and linear dichroism in Topological Weyl Semimetals.
Theory of Kerr and Faraday rotations and linear dichroism in Topological Weyl Semimetals.
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DOI：
10.1038/srep12683
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发表时间：
2015-08-03
影响因子：
4.6
通讯作者：
Trivedi N
中科院分区：
文献类型：
--
作者：
Kargarian M;Randeria M;Trivedi N
研究了在体材料中具有一对外尔节点，在表面布里渊区具有相应费米弧的拓扑外尔半金属的电磁响应。我们计算了频率相关的复电导率σαβ（ω），并考虑了拓扑θ项对麦克斯韦方程的修正，得到了各种几何条件下的克尔和法拉第转动。对于薄于波长的TWS膜，克尔和法拉第旋转，由外尔节点之间的分离确定，显着大于拓扑绝缘体。在较厚的膜中，克尔角和法拉第角可以通过选择膜厚度和衬底折射率来增强。我们发现，辐射入射到表面上的费米弧，没有克尔或法拉第旋转，但电场开发的纵向分量内的TWS，有线性二向色性信号。我们的研究结果具有一定的影响，探测在各种实验系统中的TWS阶段。
We consider the electromagnetic response of a topological Weyl semimetal (TWS) with a pair of Weyl nodes in the bulk and corresponding Fermi arcs in the surface Brillouin zone. We compute the frequency-dependent complex conductivities σαβ(ω) and also take into account the modification of Maxwell equations by the topological θ-term to obtain the Kerr and Faraday rotations in a variety of geometries. For TWS films thinner than the wavelength, the Kerr and Faraday rotations, determined by the separation between Weyl nodes, are significantly larger than in topological insulators. In thicker films, the Kerr and Faraday angles can be enhanced by choice of film thickness and substrate refractive index. We show that, for radiation incident on a surface with Fermi arcs, there is no Kerr or Faraday rotation but the electric field develops a longitudinal component inside the TWS, and there is linear dichroism signal. Our results have implications for probing the TWS phase in various experimental systems.