Current fluctuations of an interacting quantum dot

TL;DR

This paper analyzes the current fluctuations in an interacting quantum dot, revealing how electron transfer statistics are affected by interactions, with fluctuations saturating at high voltages and higher cumulants reaching a temperature-independent limit.

Contribution

It provides an exact calculation of counting statistics for an interacting quantum dot modeled as a Luttinger liquid at the Toulouse point, highlighting distinctive interaction effects on current fluctuations.

Findings

Fluctuations saturate at high voltages.

Mean current increases linearly with bias.

Higher cumulants reach a temperature-independent limit.

Abstract

We calculate the counting statistics of electron transfer through an open quantum dot with charging interaction. A dot that is connected to leads by two single-channel quantum point contacts in an in-plane magnetic field is described by a Luttinger liquid with impurity at the Toulouse point. We find that the fluctuations of the current through this conductor exhibit distinctive interaction effects. Fluctuations saturate at high voltages, while the mean current increases linearly with the bias voltage. All cumulants higher than the second one reach at large bias a temperature independent limit.