Intrinsic optical conductivity of a ${{\rm{C}}}_{2v}$ symmetric topological insulator

Abstract

In this work we analytically investigate the longitudinal optical conductivity of the C 2v symmetric topological insulator. The conductivity expressions at T = 0 are derived using the Kubo formula and expressed as a function of the ratio of the Dresselhaus and Rashba parameters that characterize the low-energy Hamiltonian. We find that the longitudinal inter-band conductivity vanishes when Dresselhaus and Rashba parameters are equal in strength, also called the persistent spin helix state. The calculations are extended to obtain the frequency-dependent real and imaginary components of the optical conductivity for the topological Kondo insulator SmB 6 which exhibits C 2v symmetric and anisotropic Dirac cones hosting topological states at X point on the surface Brillouin zone. arXiv:1509.08984v6 [cond-mat.mes-hall]

Transport properties of the topological Kondo insulator SmB 6 under the irradiation of light

“…Based on k • p theory and density functional theory, the low energy physics of the surface states of an ultrathin slab of SmB 6 at the X point can be captured by the following Hamiltonian [19,20]…”

“…[18] The surface states of SmB 6 around the X point can be described by a combination of Rashba-and Dresselhaus-like spin-orbit Hamiltonian. [19,20] The interplay between the Rashba and Dresselhaus parameters on transport properties is studied in our paper.…”