Thermalization Breakdown and Conductivity Improvement within the Interacting Dynamic Disorder Model

TL;DR

This study investigates how strong electron-electron interactions cause thermalization breakdown and enhance conductivity in a one-dimensional fermion model, providing insights into anomalous charge transport in organic superconductors.

Contribution

It introduces a novel computational approach to analyze thermalization and conductivity, revealing many-body effects that lead to conductivity improvements in correlated systems.

Findings

Long-time correlations indicate thermalization breakdown with strong e-e interactions.

Exponential decay matches analytical results without e-e interaction.

Potential explanation for conductivity enhancement in K3C60.

Abstract

Based on the framework of Kubo formulism, we develop the minimally entangled typical thermal state algorithm to study the temperature and time dependence of current-current correlation function in one-dimensional spinless fermion model, taking into account both the electron-electron (e-e) intersite interaction and the dynamic disorder induced by classical phonons. Without e-e interaction, the numerical results, showing an exponential decay of the time dependent correlation, could be precisely compared with that from the analytical derivation, namely, from the generalized Langevin equation. More importantly, when a strong enough e-e interaction is presence, we find a long-time correlation in the regime of small dynamic disorder, indicating the breakdown of thermal relaxation, which is a typical many-body effect. On the basis of this finding, we show that it might be applied to understand the metalliclike charge transport and the abnormal improvement of the conductivity with respect to the redoping experiment in K$_3$C$_{60}$, an organic superconducting material.