Statistics of the Charging Spectrum of a Two-Dimensional Coulomb Glass Island

TL;DR

This paper investigates the capacitance fluctuations of a disordered two-dimensional Coulomb island, revealing a universal distribution linked to the Coulomb gap and discussing behavior near the metal-insulator transition.

Contribution

It introduces a universal capacitance distribution for a 2D Coulomb glass and relates it to the Coulomb gap, providing insights into fluctuations near the metal-insulator transition.

Findings

Capacitance distribution is universal with dispersion comparable to the mean.

Distribution closely relates to the Coulomb gap in the density of states.

Capacitance fluctuations exhibit specific behavior near the metal-insulator transition.

Abstract

The fluctuations of capacitance of a two-dimensional island are studied in the regime of low electron concentration and strong disorder, when electrons can be considered classical particles. The universal capacitance distribution is found, with the dispersion being of the order of the average. This distribution is shown to be closely related to the shape of the Coulomb gap in the one-electron density of states of the island. Behavior of the the capacitance fluctuations near the metal - insulator transition is discussed.