THz Emission Spectroscopy of Surface Photogalvanic Effects in a Chiral Weyl Semimetal

Topological materials, and Weyl semimetals in particular, exhibit diverse optical effects. If inversion symmetry is broken, second order responses are allowed, expanding the number of methods that can be used to probe the optical properties of a material. These second order effects are also allowed at material interfaces, providing a unique tool to study their topologically important surface states. Here, we present photogalvanic effect data collected via terahertz emission spectroscopy on a chiral Weyl semimetal as a function of polarization and incident wavelength and discuss how our data reveal signatures of the topologically relevant surface states.