Thermoelectricity by Perfectly Conducting Channels in Quantum Spin Hall Systems

TL;DR

This paper theoretically investigates thermoelectric transport in 2D quantum spin Hall systems, revealing a temperature-dependent crossover from bulk to edge state dominance that affects thermoelectric efficiency.

Contribution

It introduces a theoretical model showing how perfectly conducting edge channels influence thermoelectric properties in quantum spin Hall systems across temperatures.

Findings

Bulk states dominate at high temperatures.

Edge channels become dominant at low temperatures.

Figure of merit varies non-monotonically with temperature.

Abstract

Thermoelectric transport of two-dimensional quantum spin Hall systems are theoretically studied in narrow ribbon geometry. We find that at high temperature electrons in the bulk states dominate. By lowering temperature, the "perfectly conducting" edge channels becomes dominant, and a bulk-to-edge crossover occurs. Correspondingly, by lowering temperature, the figure of merit first decreases and then will increase again due to edge-state-dominated thermoelectric transport.