Distribution of residence times as a marker to distinguish different pathways for quantum transport

TL;DR

This paper investigates the distribution of residence times in quantum transport through nanoscale systems, revealing how electron correlations influence tunnelling pathways and their statistical properties.

Contribution

It introduces a quantum master equation approach to distinguish and analyze different electron tunnelling pathways and their residence time distributions.

Findings

Electron correlations suppress differences between tunnelling paths.

Distribution of residence times characterizes tunnelling pathways.

Quantum noise impacts tunnelling event timing.

Abstract

Electron transport through a nanoscale system is an inherently stochastic quantum mechanical process. Electric current is a time series of electron tunnelling events separated by random intervals. Thermal and quantum noise are two sources of this randomness. In this paper, we used the quantum master equation to consider the following questions: (i) Given that an electron has tunnelled into the electronically unoccupied system from the source electrode at some particular time, how long is it until an electron tunnels out to the drain electrode to leave the system electronically unoccupied, where there were no intermediate tunnelling events ("the" tunnelling path)? (ii) Given that an electron has tunnelled into the unoccupied system from the source electrode at some particular time, how long is it until an electron tunnels out to the drain electrode to leave the system electronically unoccupied, where there were no intermediate tunnelling events ("an" tunnelling path)? (iii) What are the distributions of these times? We show that electron correlations suppress the difference between "the" and "an" electron tunnelling paths.