Strongly enhanced thermal transport in a lightly doped Mott insulator at low temperature

TL;DR

This paper demonstrates that lightly doped Mott insulators exhibit significantly enhanced electronic thermal transport at low temperatures, with universal behavior and large thermoelectric efficiency, explained through a Falicov-Kimball model analysis.

Contribution

It reveals universal low-temperature thermal transport properties in lightly doped Mott insulators using a dynamical mean-field theory approach.

Findings

Universal behavior of thermal transport independent of interaction strength

Large Lorenz number in a crossover region with high thermoelectric figure-of-merit

Results are generic for lightly doped Mott insulators under specific conditions

Abstract

We show how a lightly doped Mott insulator has hugely enhanced electronic thermal transport at low temperature. It displays universal behavior independent of the interaction strength when the carriers can be treated as nondegenerate fermions and a nonuniversal "crossover" region where the Lorenz number grows to large values, while still maintaining a large thermoelectric figure-of-merit. The electron dynamics are described by the Falicov-Kimball model which is solved for arbitrary large on-site correlation with a dynamical mean-field theory algorithm on a Bethe lattice. We show how these results are generic for lightly doped Mott insulators as long as the renormalized Fermi liquid scale is pushed to very low temperature and the system is not magnetically ordered.