Thermoelectric Effect in Topological Insulators

Improving the thermoelectric figure of merit $zT$ is one of the greatest challenges in material science. The recent discovery of topological insulators (TIs) offers new promise in this prospect. In this talk, we demonstrate theoretically that $zT$ is strongly size dependent in TIs, and the size parameter can be tuned to enhance $zT$ to be significantly greater than 1. Furthermore, we show that the lifetime of the edge states in TIs is strongly energy dependent, leading to large and anomalous Seebeck effects with an opposite sign to the Hall effect. Some recent experimental progress will also be introduced.