Charge Disorder in Granular Metallic Films

TL;DR

This paper demonstrates that charge disorder in 2D granular metallic films suppresses the Kosterlitz-Thouless transition, alters conductance behavior, and explains experimental observations by reducing the Coulomb gap.

Contribution

It reveals that charge disorder universally destroys the charge-unbinding transition in 2D granular arrays and impacts their electrical properties.

Findings

Charge disorder destroys the Kosterlitz-Thouless transition.

Conductance follows Arrhenius temperature dependence.

Disorder reduces the Coulomb gap, aligning with experimental data.

Abstract

It is shown that practically any physically relevant random distribution of offset charges destroys the Kosterlitz-Thouless-Berezinskii charge-unbinding phase transition in two dimensional normal and superconducting granular arrays and films. The array conductance obeys the Arrenius dependence on temperature. Offset charge disorder decreases the effective Coulomb gap of the system and may account for recent experimental findings in two dimensional arrays of tunnel junctions.