Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg1−xCdxTe

Abstract

Terahertz photoconductivity in heterostructures based on n-type Hg1−xCdxTe epitaxial films both in the topological phase (x 0.16, normal band structure) has been studied. We show that both the positive photoresponse in films with x 0.16 have no low-energy threshold. The observed non-threshold positive photoconductivity is discussed in terms of a qualitative model that takes into account a 3D potential well and 2D topological Dirac states coexisting in a smooth topological heterojunction.

Keywords

• terahertz radiation
• topological insulator
• photoconductivity