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

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.