Off-resonant polarized light-controlled thermoelectric transport in ultrathin topological insulators

Abstract

We study thermoelectric transport in ultrathin topological insulators under the application of circularly polarized off-resonant light of frequency {\Omega} and amplitude A. We derive analytical expressions for the band structure, orbital magnetization Morb, and the thermal (\k{appa}xy) and Nernst ({\alpha}xy) conductivities. Reversing the light polarization from right to left leads to an exchange of the conduction and valence bands of the symmetric and antisymmetric surface states and to a sign change in Morb,{\alpha}xy, and \k{appa}xy. Varying the sample thickness or A/{\Omega} leads to a strong enhancement of Morb and {\alpha}xy. These effects, accessible to experiments, open the possibility for selective, state-exchanged excitations under light and the conversion of heat to electric energy.