Charge Density Wave and Superconductivity in the Disordered Holstein Model

TL;DR

This study uses quantum Monte Carlo simulations to show that disorder suppresses charge density wave order and promotes superconductivity in the Holstein model, aligning with recent experimental observations.

Contribution

It demonstrates, through exact simulations, how disorder can induce superconductivity by disrupting charge density wave correlations in the Holstein model.

Findings

Disorder suppresses charge density wave correlations.

Superconductivity emerges as charge order diminishes.

Results align qualitatively with experimental observations.

Abstract

The interplay between electron-electron correlations and disorder has been a central theme of condensed matter physics over the last several decades, with particular interest in the possibility that interactions might cause delocalization of an Anderson insulator into a metallic state, and the disrupting effects of randomness on magnetic order and the Mott phase. Here we extend this physics to explore electron-phonon interactions and show, via exact quantum Monte Carlo simulations, that the suppression of the charge density wave correlations in the half-filled Holstein model by disorder can stabilize a superconducting phase. Our simulations thus capture qualitatively the suppression of charge ordered phases and emergent superconductivity recently seen experimentally.