Competition between zero bias anomaly and proximity effect in disordered systems

TL;DR

This paper explores how disorder and Coulomb interactions suppress the proximity effect in mesoscopic normal metal/superconductor systems, providing a theoretical framework and potential experimental implications.

Contribution

It introduces a mechanism showing disorder amplifies Coulomb interaction effects, leading to the complete suppression of the proximity effect in strongly disordered systems.

Findings

Disorder amplifies Coulomb interaction effects.

Proximity effect vanishes in strongly disordered systems.

Derived an expression for the tunneling density of states.

Abstract

We investigate the suppression of the proximity effect in mesoscopic normal metal/superconductor systems induced by Coulomb interaction. We identify and elucidate the mechanism by which disorder leads to an amplification of this effect. In particular, for strong enough disorder, the proximity effect is shown to vanish. An expression for the tunneling density of states is obtained, and experimental applications are discussed.