Measurement of Counting Statistics of Electron Transport in a Tunnel Junction

TL;DR

This paper reports measurements of electron current fluctuations in a tunnel junction, confirming that the counting statistics follow a Poisson distribution due to electron charge discreteness, with detailed analysis of the first three moments.

Contribution

The study provides the first simultaneous measurement of the first three moments of tunnel current counting statistics, validating the Poissonian model in a low-environment coupling regime.

Findings

Counting statistics follow a Poisson distribution.

First three moments of current fluctuations measured.

Results confirm theoretical predictions for tunneling transport.

Abstract

We present measurements of the time-dependent fluctuations in electrical current in a voltage-biased tunnel junction. We were able to simultaneously extract the first three moments of the tunnel current counting statistics. Detailed comparison of the second and the third moment reveals that counting statistics is accurately described by the Poissonian distribution expected for spontaneous current fluctuations due to electron charge discreteness, realized in tunneling transport at negligible coupling to environment.