Chiral filtration of light by Weyl-semimetal medium

TL;DR

This paper predicts that Weyl-semimetals can act as polarization filters by exploiting their topological properties, leading to polarization-dependent electromagnetic transmission and rotation effects.

Contribution

It introduces the concept of using Weyl-semimetals for chiral light filtration based on their topological and electromagnetic properties.

Findings

Transmission depends on polarization orientation relative to the gyration vector

Transition from isotropic dielectric to chiral selective medium occurs with polarization change

Weyl-semimetals can function as polarization filters

Abstract

Recently discussed topological materials Weyl-semimetals (WSs) combine both: high electron mobility comparable with graphene and unique topological protection of Dirac points. We present novel results related to electromagnetic field propagation through WSs. It is predicted that transmission of the normally incident polarized electromagnetic wave (EMW) through the WS strongly depends on the orientation of polarization with respect to a gyration vector $\mathbf{g}$. The latter is related to the vector-parameter $\mathbf{b}$, which represents the separation between the Weyl nodes of opposite chirality in the first Brillouin zone. By changing the polarization of the incident EMW with respect to the gyration vector $\mathbf{g}$ the system undergoes the transition from the isotropic dielectric to the medium with Kerr- or Faraday-like rotation of polarization and finally to the system with chiral selective electromagnetic field. It is shown that WSs can be applied as the polarization filters.