Analysis of the Disorder-Induced Zero Bias Anomaly in the Anderson-Hubbard Model

TL;DR

This paper investigates the zero bias anomaly in the density of states of the two-dimensional Anderson-Hubbard model, revealing its origin from nonlocal inelastic self-energy responses to disorder, with implications for theoretical modeling.

Contribution

It introduces an analytical approach linking the ZBA to nonlocal self-energy effects, providing a simplified expression for the density of states in the Anderson-Hubbard model.

Findings

ZBA width is proportional to hopping amplitude t

ZBA is independent of interaction strength and disorder potential

Analytical formalism reproduces key features of the ZBA

Abstract

Using a combination of numerical and analytical calculations, we study the disorder-induced zero bias anomaly (ZBA) in the density of states of strongly-correlated systems modeled by the two dimensional Anderson-Hubbard model. We find that the ZBA comes from the response of the nonlocal inelastic self-energy to the disorder potential, a result which has implications for theoretical approaches that retain only the local self-energy. Using an approximate analytic form for the self-energy, we derive an expression for the density of states of the two-site Anderson-Hubbard model. Our formalism reproduces the essential features of the ZBA, namely that the width is proportional to the hopping amplitude $t$ and is independent of the interaction strength and disorder potential.