Surface conductivity in antiferromagnetic semiconductor CrSb2

Abstract

The contribution of bulk and surface to the electrical resistance along crystallographic b and c axes as a function of crystal thickness gives evidence for temperature-independent surface states in an antiferromagnetic narrow-gap semiconductor CrSb2. Angle-resolved photoemission spectroscopy shows a clear electronlike pocket in the Γ-Z direction which is absent in the bulk band structure. First-principles calculations also confirm the existence of metallic surface states inside the bulk gap. Whereas combined experimental probes point to enhanced surface conduction similar to topological insulators, surface states are trivial since CrSb2 exhibits no band inversion.