Quantized circular photogalvanic effect in Weyl semimetals

Abstract The circular photogalvanic effect (CPGE) is the part of a photocurrent that switches depending on the sense of circular polarization of the incident light. It has been consistently observed in systems without inversion symmetry and depends on non-universal material details. Here we find that in a class of Weyl semimetals (for example, SrSi 2 ) and three-dimensional Rashba materials (for example, doped Te) without inversion and mirror symmetries, the injection contribution to the CPGE trace is effectively quantized in terms of the fundamental constants e , h , c and "Equation missing" with no material-dependent parameters. This is so because the CPGE directly measures the topological charge of Weyl…

• NS
  National Science Foundation

  Awards: 1507141, NSF DMR-1507141, DMR-1507141
• GA
  Gordon and Betty Moore Foundation
• DO
  Division of Materials Research

  Award: NSF DMR-1507141