Counting statistics of charge pumping in an open system

TL;DR

This paper analyzes the counting statistics of charge pumping in open systems, revealing universal Poissonian processes, super-Poissonian noise characteristics, and a method to determine charge quantum through noise measurement.

Contribution

It introduces a universal form for electron counting statistics in open systems and proposes a parameter tuning method to optimize current-to-noise ratio for charge quantum measurement.

Findings

Charge transmission follows two uncorrelated Poisson processes.

Overall noise is super-Poissonian but can be minimized.

Noise measurement enables parameter-free charge quantum determination.

Abstract

Electron counting statistics of a current pump in an open system has universal form in the weak pumping current regime. In the time domain, charge transmission is described by two uncorrelated Poisson processes, corresponding to electron transmission in the right and left direction. Overall noise is super-poissonian, and can be reduced to poissonian by tuning the amplitude and phase of driving signal so that current to noise ratio is maximized. Measuring noise in this regime provides a new method for determining charge quantum in an open system without any fitting parameters.