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

TL;DR

This paper investigates how off-resonant circularly polarized light influences thermoelectric properties in ultrathin topological insulators, revealing controllable band structure changes and enhanced thermoelectric responses.

Contribution

It provides analytical models linking light polarization to thermoelectric transport, demonstrating tunable effects and potential for energy conversion applications in topological insulators.

Findings

Reversing light polarization exchanges conduction and valence bands.

Varying thickness or light parameters enhances magnetization and Nernst conductivity.

Effects are experimentally accessible and enable controlled heat-to-electricity conversion.

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.