Strong feedback and current noise in nanoelectromechanical systems

TL;DR

This paper demonstrates a strong feedback regime in nanoelectromechanical systems where mechanical oscillations significantly modify current and noise, revealing new insights into noise behavior beyond traditional Poisson limits.

Contribution

It introduces the feasibility of achieving strong feedback in single-electron tunneling devices coupled to oscillators, highlighting the role of energy-dependent tunnel amplitudes.

Findings

Mechanical oscillations are generated under strong feedback.

Current noise can exceed Poisson value due to mechanical effects.

Fast tunnel rates amplify mechanical contributions to noise.

Abstract

We demonstrate the feasibility of a strong feedback regime for a single-electron tunneling device weakly coupled to an underdamped single-mode oscillator. In this regime, mechanical oscillations are generated and the current is strongly modified whereas the current noise is parametrically big with respect to the Poisson value. This regime requires energy dependence of the tunnel amplitudes. For sufficiently fast tunnel rates the mechanical contribution to current noise can exceed the Poisson value even beyond the strong feedback regime.