Frequency Scales for Current Statistics of Mesoscopic Conductors

TL;DR

This paper calculates the frequency-dependent third cumulant of current in a chaotic cavity, revealing unique dispersion effects related to charge relaxation and dwell time, with suppression under certain contact transparency conditions.

Contribution

It introduces a detailed calculation of the third current cumulant's frequency dependence in mesoscopic conductors with arbitrary contact transparency, highlighting novel dispersion phenomena.

Findings

Frequency dependence differs from conventional noise.

Dispersion at inverse RC time and dwell time.

Suppression when contact transparencies are extreme.

Abstract

We calculate the third cumulant of current in a chaotic cavity with contacts of arbitrary transparency as a function of frequency. Its frequency dependence drastically differs from that of the conventional noise. In addition to a dispersion at the inverse RC time characteristic of charge relaxation, it has a low-frequency dispersion at the inverse dwell time of electrons in the cavity. This effect is suppressed if both contacts have either large or small transparencies.