Topological Features in the Optical Response of Nodal Ring Semimetals

Topological nodal ring semimetals can have highly anisotropic energy dispersion which gives rise to anisotropic optical conductivity tensor and peculiar properties of the normal electromagnetic modes, or polaritons, in these materials. Here we calculate the optical conductivity and spectra of transmitted and reflected electromagnetic waves for different types of nodal ring semimetals. We show how distinctive spectral and polarization features of the polaritons can be used to extract information about the topological properties of these fascinating materials.