Transport Properties of the Infinite Dimensional Hubbard Model

TL;DR

This paper investigates the transport properties of the Hubbard model in infinite dimensions, revealing how conductivity and resistivity evolve with interaction strength, doping, and temperature, highlighting a crossover from metallic to insulating behavior.

Contribution

It provides a detailed analysis of optical conductivity and resistivity in the infinite-dimensional Hubbard model, including the effects of doping and temperature on electronic phases.

Findings

Observation of a crossover from Fermi-liquid to insulator at half filling with increasing U.

Identification of a T^2 dependence in low-temperature resistivity indicating mass enhancement.

High-temperature crossover into a semi-metallic regime.

Abstract

Results for the optical conductivity and resistivity of the Hubbard model in infinite spatial dimensions are presented. At half filling we observe a gradual crossover from a normal Fermi-liquid with a Drude peak at $\omega=0$ in the optical conductivity to an insulator as a function of $U$ for temperatures above the antiferromagnetic phase transition. When doped, the ``insulator'' becomes a Fermi-liquid with a corresponding temperature dependence of the optical conductivity and resistivity. We find a $T^2$-coefficient in the low temperature resistivity which suggests that the carriers in the system acquire a considerable mass-enhancement due to the strong local correlations. At high temperatures, a crossover into a semi-metallic regime takes place.