Effect of dephasing on the current statistics of mesoscopic devices

TL;DR

This paper studies how dephasing influences current fluctuations in mesoscopic devices, revealing that higher order cumulants do not offer extra information about decoherence beyond the average current.

Contribution

It introduces a statistical model to analyze the impact of partial coherence on current cumulants in mesoscopic conductors, covering intermediate regimes of decoherence.

Findings

Dephasing affects average current, shot noise, and higher cumulants similarly.

Higher order cumulants do not provide additional information on decoherence beyond the average current.

The model recovers known results in fully coherent and incoherent limits.

Abstract

We investigate the effects of dephasing on the current statistics of mesoscopic conductors with a recently developed statistical model, focusing in particular on mesoscopic cavities and Aharonov-Bohm rings. For such devices, we analyze the influence of an arbitrary degree of decoherence on the cumulants of the current. We recover known results for the limiting cases of fully coherent and totally incoherent transport and are able to obtain detailed information on the intermediate regime of partial coherence for a varying number of open channels. We show that dephasing affects the average current, shot noise, and higher order cumulants in a quantitatively and qualitatively similar way, and that consequently shot noise or higher order cumulants of the current do not provide information on decoherence additional or complementary to what can be already obtained from the average current.