Electrical conductivity of statically perturbed topological crystalline insulators

Abstract

We theoretically investigate the electrical conductivity (EC) of topological crystalline insulators SnTe (001) and related alloys in the presence of external static local perturbations employing a continuum model and the Kubo-Greenwood formalism. Particularly, we have found the conditions for which the Dirac and saddle points can be altered in the presence of the perpendicular electric field, the on-site energy difference and the exchange field. Then, the EC of these alterations is addressed for potentials smaller and larger than the intervalley scattering parameter. Numerical results show that the band gap opens by the exchange field, while the electric field and on-site energy difference shift the Dirac/saddle points and the Fermi level, respectively. These phenomena result in the increasing and decreasing of the EC with electric field/on-site energy difference and exchange field, respectively. Finally, we find that the EC becomes non-zero at zero temperature when the Fermi level is shifted. These findings will bring applications to topological electronics.