Electron Transport in Granular Metals

TL;DR

This paper investigates electron transport in long granular metal arrays with strong inter-grain coupling, revealing activated conductance behavior and a large energy gap related to charge soliton creation.

Contribution

It introduces a theoretical analysis of thermodynamic and transport properties showing a large energy scale T* associated with charge solitons.

Findings

Conductance exhibits activated behavior ~exp(-T*/T).

Thermodynamic density of states shows similar activated dependence.

The energy gap T* exceeds the breakdown energy of perturbation theory.

Abstract

We consider thermodynamic and transport properties of a long granular array with strongly connected grains (inter-grain conductance g>>1.) We find that the system exhibits activated behavior of conductance and thermodynamic density of states ~exp(-T*/T) where the gap, T*, is parametrically larger than the energy at which conventional perturbation theory breaks down. The scale T* represents energy needed to create a long single-electron charge soliton propagating through the array.