Granular systems in the Coulomb blockade regime

TL;DR

This paper investigates disordered granular systems in the Coulomb blockade regime, revealing how charging effects induce insulating behavior and a possible zero-temperature transition between metallic and insulating phases.

Contribution

It introduces an effective medium approximation to analyze the impact of intragrain charging energy on the electronic phases of granular systems.

Findings

Charging energy causes a Coulomb gap and insulating behavior at low temperatures.

A zero-temperature transition between metallic and insulating phases is possible due to non-equilibrium effects.

The study provides a theoretical framework for understanding Coulomb blockade phenomena in disordered systems.

Abstract

Disordered granular systems, at temperatures where charging effects are important, are studied, by means of an effective medium approximation. The intragrain charging energy leads to insulating behavior at low temperatures, with a well defined Coulomb gap. Non equilibrium effects can give rise to a zero temperature transition between a metallic, gapless phase, and an insulating phase.