Non-monotonic temperature dependence of thermopower in strongly correlated electron systems

TL;DR

This paper investigates how thermopower in strongly correlated electron systems varies with temperature, revealing a non-monotonic behavior due to Coulomb interactions and crossover phenomena, with implications for transition metal oxides.

Contribution

It provides a theoretical analysis of thermopower's non-monotonic temperature dependence in the Hubbard model using dynamical mean-field theory, linking it to experimental observations.

Findings

Thermopower shows non-monotonic temperature dependence.

Thermopower approaches Mott-Heikes limits at high temperatures.

Magnetic field influences thermopower behavior.

Abstract

We examine the temperature dependence of thermopower in the single band Hubbard model using dynamical mean-field theory. The strong Coulomb interaction brings about the coherent-to-incoherent crossover as temperature increases. As a result, the thermopower exhibits non-monotonic temperature dependence and asymptotically approaches values given by the Mott-Heikes formula. In the light of our theoretical result, we discuss the thermopower in some transition metal oxides. The magnetic field dependence of the thermopower is also discussed.