Current fluctuations in composite conductors: Beyond the second cumulant

TL;DR

This paper uses the non-linear sigma-model to analyze higher-order current fluctuations in composite conductors with diffusive elements, providing explicit predictions for the third cumulant and Coulomb corrections that can be experimentally tested.

Contribution

It presents a novel calculation of the frequency-dependent third current cumulant in composite conductors with Coulomb interaction effects.

Findings

Explicit expression for the third current cumulant.

Identification of Coulomb interaction corrections to shot noise.

Predictions suitable for experimental verification.

Abstract

Employing the non-linear $\sigma$-model we analyze current fluctuations in coherent composite conductors which contain a diffusive element in-between two tunnel barriers. For such systems we explicitly evaluate the frequency-dependent third current cumulant which also determines the leading Coulomb interaction correction to shot noise. Our predictions can be directly tested in future experiments.