Magneto-polaritons in Weyl semimetals

Exotic topological and transport properties of Weyl semimetals generated a lot of excitement in the condensed matter community. Here we show that Weyl semimetals in a strong magnetic field are highly unusual optical materials. The hybridization of magnetoplasmons with electromagnetic waves leads to fascinating optical phenomena involving magnetopolaritons: hyperbolic dispersion, the absence of Landau damping for strongly localized excitations, photonic stop bands, coupling-induced transparency, efficient polarization conversion, and pulse compression, to name a few. We show that optical spectroscopic techniques provide a ``clean'' way of detecting properties of low-energy electron states and in particular the chiral anomaly. Moreover, Weyl semimetals show strong promise for future photonic chips enabling a wide array of broadband optoelectronic applications, such as polarizers, modulators, switches, and pulse shapers for mid-infrared through terahertz wavelengths.