Nonlinear voltage dependence of shot noise

TL;DR

This paper develops a theoretical framework for understanding how shot noise in mesoscopic conductors depends nonlinearly on bias voltage, ensuring gauge invariance and providing explicit formulas for small and finite voltages.

Contribution

It introduces a gauge-invariant theoretical formulation for nonlinear shot noise spectra, including explicit expressions and a closed-form solution in the wideband limit.

Findings

Derived explicit nonlinear noise spectra at small voltages

Obtained a closed-form solution in the wideband limit

Ensured gauge invariance at the nonlinear level

Abstract

The current noise in a multi-probe mesoscopic conductor can have a nonlinear dependence on the strength of driving bias voltage. This paper presents a theoretical formulation for the nonlinear noise spectra. We pay special attention to maintain gauge invariance at the nonlinear level. At small but finite voltages, explicit expressions for nonlinear noise spectra, expanded order by order in the bias, have been derived. In the wideband limit, a closed form solution of the noise spectra for finite voltages is obtained.