Large current noise in nanoelectromechanical systems close to continuous mechanical instabilities

TL;DR

This paper studies how nanoelectromechanical systems near a mechanical instability exhibit significantly increased current noise, especially in single-electron transistors close to Euler buckling, due to charge fluctuation sensitivity.

Contribution

It demonstrates the exponential increase in current noise near the Euler buckling instability and explains it through telegraph noise mechanisms.

Findings

Current noise becomes super-Poissonian near the instability

Vibrational frequency approaches zero, increasing charge fluctuation sensitivity

Exponential enhancement of noise observed in single-electron transistors

Abstract

We investigate the current noise of nanoelectromechanical systems close to a continuous mechanical instability. In the vicinity of the latter, the vibrational frequency of the nanomechanical system vanishes, rendering the system very sensitive to charge fluctuations and, hence, resulting in very large (super-Poissonian) current noise. Specifically, we consider a suspended single-electron transistor close to the Euler buckling instability. We show that such a system exhibits an exponential enhancement of the current noise when approaching the Euler instability which we explain in terms of telegraph noise.