Current and current fluctuations in quantum shuttles

TL;DR

This paper reviews quantum electron shuttles, focusing on their quantum mechanical properties, theoretical analysis tools, and key results on current and noise, highlighting the physics and experimental context.

Contribution

It introduces theoretical tools and methods for analyzing quantum electron shuttles, emphasizing the quantum limit and large numerical problem handling.

Findings

Analysis of current and noise in quantum shuttles

Application of generalized master equations and Wigner functions

Discussion of experimental relevance

Abstract

We review the properties of electron shuttles, i.e. nanoelectromechanical devices that transport electrons one-by-one by utilizing a combination of electronic and mechanical degrees of freedom. We focus on the extreme quantum limit, where the mechanical motion is quantized. We introduce the main theoretical tools needed for the analysis, e.g. generalized master equations and Wigner functions, and we outline the methods how the resulting large numerical problems can be handled. Illustrative results are given for current, noise, and full counting statistics for a number of model systems. Throughout the review we focus on the physics behind the various approximations, and some simple examples are given to illustrate the theoretical concepts. We also comment on the experimental situation.