Electron shuttle as an autonomous single-electron source

TL;DR

This paper investigates the autonomous electron shuttle's ability to serve as a single-electron source using self-oscillation and waiting time distributions, revealing smooth regime transitions and proposing design improvements for better precision.

Contribution

It introduces the use of waiting time distributions to analyze autonomous electron shuttles and proposes a new design to enhance charge transmission accuracy.

Findings

The shuttle exhibits a smooth transition between three operational regimes.

It can function as a single-electron source with moderate precision.

A new design significantly reduces charge transmission errors.

Abstract

The majority of experimental realizations of single-electron sources rely on the periodic manipulation of the tunnel junctions through their gate voltages, and thus require a high level of control over the system. To circumvent the necessity of external driving, we utilize the self-oscillatory behavior of the electron shuttle. By means of waiting time distributions, which had not been applied to this autonomous system before, we extensively assess the performance of the shuttle as a single-electron source. We unveil a smooth transition between three regimes, whereas previous studies at the same mean field level of description only predict a sharp bifurcation based on the time-averaged electron current. Over the parameter range of already existing experimental realizations the electron shuttle can perform as a single-electron source, albeit with moderate precision. We propose an alternative design of the position-dependent tunneling rates, which significantly decreases the relative error of charge transmission, and thus paves the way for the realization of autonomous single-electron sources.