Temperature dependence of the zero-bias anomaly in the Anderson-Hubbard model: Insights from an ensemble of two-site systems

TL;DR

This study investigates how temperature affects the zero-bias anomaly in a simplified two-site Anderson-Hubbard model, revealing temperature-induced features similar to those observed in more complex systems.

Contribution

It provides new insights into the temperature dependence of the zero-bias anomaly using an ensemble of two-site systems, bridging simple models and complex materials.

Findings

Zero-bias anomaly appears at small nonzero temperatures in the atomic limit.

Hopping enhances the zero-bias anomaly at low temperatures.

At higher temperatures, the anomaly diminishes and is filled in.

Abstract

Motivated by experiments on doped transition metal oxides, this paper considers the interplay of interactions, disorder, kinetic energy and temperature in a simple system. An ensemble of two-site Anderson-Hubbard model systems has already been shown to display a zero-bias anomaly which shares features with that found in the two-dimensional Anderson-Hubbard model. Here the temperature dependence of the density of states of this ensemble is examined. In the atomic limit, there is no zero-bias anomaly at zero temperature, but one develops at small nonzero temperatures. With hopping, small temperatures augment the zero-temperature kinetic-energy-driven zero-bias anomaly, while at larger temperatures the anomaly is filled in.