Thermal transport in the Falicov-Kimball model on a Bethe lattice

Abstract

We calculate thermal transport in the Falicov-Kimball model on an infinite-coordination-number Bethe lattice. We perform numerical calculations of the thermoelectric characteristics and concentrate on finding materials parameters for which the electronic thermoelectric figure-of-merit ZT is large, suggesting potential cooling and power generation applications. Surprisingly, the Bethe lattice has significant qualitative and quantitative differences with the previously studied hypercubic lattice. At low temperature it is unlikely that these systems can be employed in thermoelectric devices due to the low conductivities and due to a larger lattice contribution to the thermal conductivity $\kappa_L$, but at high temperature, the thermoelectric parameters appear more promising for devices due to a significant enhancement of ZT and a smaller relative contribution by the lattice thermal conductivity.