Coulomb Blockade without Tunnel Junctions

TL;DR

This paper demonstrates that Coulomb blockade effects can occur without tunnel junctions, using arbitrary scatterers like diffusive ones, by deriving an effective action that describes their behavior.

Contribution

It introduces a theoretical framework for Coulomb blockade without tunnel junctions, replacing them with arbitrary scatterers and analyzing their effects.

Findings

Diffusive scatterers can sustain single electron effects.

An effective action formalism for arbitrary scatterers is developed.

Fluctuations of the effective charging energy are analyzed.

Abstract

We find that tunnel junctions are not needed to provide single electron effects in a metallic island. Eventually the tunnel junction may be replaced by an arbitrary scatterer. It is important that even a {\it diffusive} scatterer provides a sufficient isolation for single electron effects to persist. To formulate this in exact terms, we derive and analyze the effective action that describes an arbitrary scatterer. We also consider the fluctuations of the effective charging energy.