Dynamical thermal response functions for strongly correlated one-dimensional systems

TL;DR

This paper investigates the thermal response functions of one-dimensional Hubbard and spinless fermion models, calculating conductivities and thermoelectric properties, and explores how frustration affects these properties at various temperatures.

Contribution

It provides exact diagonalization results for dynamical response functions and examines the impact of frustration on thermoelectric properties in 1D models.

Findings

Frustration enhances thermopower at intermediate and low temperatures.

Calculated electrical, thermoelectrical, and thermal conductivities using the Kubo formalism.

Identified effects of second neighbor hopping on thermoelectric efficiency.

Abstract

In this article we study the thermal response functions for two one-dimensional models, namely the Hubbard and spin-less fermion $t$-$V$ models. By exactly diagonalizing finite sized systems we calculate dynamical electrical, thermoelectrical, and thermal conductivities via the Kubo formalism. The thermopower (Seebeck coefficient), Lorenz number, and dimensionless figure of merit are then constructed which are quantities of great interest to the physics community both theoretically and experimentally. We also geometrically frustrate these systems and destroy integrability by the inclusion of a second neighbor hop. These frustrated systems are shown to have enhanced thermopower and Lorenz number at intermediate and low temperatures.