Can disorder act as a chemical pressure? An optical study of the Hubbard model

TL;DR

This study uses dynamical mean-field theory to explore how disorder in the Hubbard model can mimic chemical pressure by increasing effective bandwidth, revealing optical property similarities with chemically doped systems.

Contribution

It demonstrates that disorder can act as a form of chemical pressure, enhancing metallic behavior and increasing bandwidth, with optical properties matching experimental observations.

Findings

Disorder can enhance metallic behavior in the Hubbard model.

Optical properties under disorder resemble those under chemical doping.

Disorder-induced effects differ from other bandwidth tuning mechanisms.

Abstract

The optical properties have been studied using the dynamical mean-field theory (DMFT) on a disordered Hubbard model. Despite the fact that disorder turns a metal to an insulator in high dimensional correlated materials, we notice that it can enhance certain metallic behavior as if a chemical pressure is applied to the system resulting in an increase of the effective lattice bandwidth (BW). We study optical properties in such a scenario and compare results with experiments where the BW is changed through chemical doping and obtain remarkable similarities vindicating our claim. We also make a point that these similarities differ from some other forms of BW tuned optical effects.