Zero--Bias Anomaly in Finite Size Systems

TL;DR

This paper investigates a unique zero-bias anomaly in the density of states of small disordered interacting systems, exploring its behavior across different regimes and effects of environmental coupling.

Contribution

It introduces a detailed analysis of the zero-bias anomaly in zero-dimensional systems, bridging Coulomb blockade and Altshuler-Aronov effects, including environmental influences.

Findings

The anomaly interpolates between Coulomb blockade and Altshuler-Aronov regimes.

Environmental coupling screens interactions, altering the density of states.

The study provides a unified understanding of zero-bias anomalies in small systems.

Abstract

The small energy anomaly in the single particle density of states of disordered interacting systems is studied for the zero dimensional case. This anomaly interpolates between the non--perturbative Coulomb blockade and the perturbative limit, the latter being an extension of the Altshuler--Aronov zero bias anomaly at d=0. Coupling of the zero dimensional system to a dissipative environment leads to an effective screening of the interaction and a modification of the density of states.