Full counting statistics and conditional evolution in a nanoelectromechanical system

TL;DR

This paper theoretically analyzes the full charge transfer distribution and conditional evolution in a nanoelectromechanical system, revealing non-Gaussian effects and complex back-action beyond thermal bath models.

Contribution

It introduces a detailed theoretical framework for understanding charge transfer statistics and oscillator dynamics in nanoelectromechanical systems, highlighting non-Gaussian phenomena.

Findings

Weak coupling can still significantly alter tunneling statistics.

Oscillator energy distribution can become localized and non-thermal.

Non-Gaussian correlations indicate complex back-action effects.

Abstract

We study theoretically the full distribution of transferred charge in a tunnel junction (or quantum point contact) coupled to a nanomechanical oscillator, as well as the conditional evolution of the oscillator. Even if the oscillator is very weakly coupled to the tunnel junction, it can strongly affect the tunneling statistics and lead to a highly non-Gaussian distribution. Conversely, given a particular measurement history of the current, the oscillator energy distribution may be localized and highly non-thermal. We also discuss non-Gaussian correlations between the oscillator motion and tunneling electrons; these show that the tunneling back-action cannot be fully described as an effective thermal bath coupled to the oscillator.