Shot noise in frustrated single-electron arrays

TL;DR

This paper investigates shot noise in two-dimensional frustrated single-electron arrays, revealing that noise is strongly colored at low currents and that thermal fluctuations significantly influence the Fano factor.

Contribution

It provides the first detailed numerical analysis of shot noise in 2D frustrated single-electron arrays, highlighting differences from 1D arrays and effects of thermal fluctuations.

Findings

Shot noise in 2D arrays is strongly colored at low currents.

Fano factor can exceed unity due to electron/hole avalanches.

Thermal fluctuations suppress the Fano factor below 1.

Abstract

We have carried out numerical simulations of shot noise in 2D arrays of single-electron islands with random background charges. The results show that in contrast with the 1D arrays, at low currents the current noise is strongly colored, and its spectral density levels off at very low frequencies. The Fano factor may be much larger than unity, due to the remnants of single-electron/hole avalanches. However, even very small thermal fluctuations reduce the Fano factor below 1 for almost any bias.