Temperature dependent third cumulant of tunneling noise

TL;DR

This paper shows that the third cumulant of tunneling noise, contrary to Poisson predictions, depends strongly on temperature and can even change sign due to environmental feedback effects.

Contribution

It provides a theoretical explanation for the temperature dependence and sign change of the third cumulant in tunneling noise, considering electromagnetic environment feedback.

Findings

Third cumulant varies with temperature

It can change sign from positive to negative

Environmental feedback influences noise statistics

Abstract

Poisson statistics predicts that the shot noise in a tunnel junction has a temperature independent third cumulant e^2\I, determined solely by the mean current I. Experimental data, however, show a puzzling temperature dependence. We demonstrate theoretically that the third cumulant becomes strongly temperature dependent and may even change sign as a result of feedback from the electromagnetic environment. In the limit of a noninvasive (zero-impedance) measurement circuit in thermal equilibrium with the junction, we find that the third cumulant crosses over from e^2/I at low temperatures to -e^2/I at high temperatures.