Nonresonant high frequency excitation of mechanical vibrations in graphene based nanoresonator

TL;DR

This paper theoretically investigates how high-frequency, nonresonant electrostatic excitation can induce self-sustained mechanical vibrations in a graphene nanoresonator through retardation effects in the electronic subsystem.

Contribution

It introduces a novel mechanism for exciting large-amplitude vibrations in graphene nanoresonators via nonresonant high-frequency electrostatic driving.

Findings

Retardation effects enable effective pumping of mechanical vibrations.

A critical voltage amplitude induces a transition to self-sustained oscillations.

The system exhibits nonlinear damping saturation leading to stable oscillations.

Abstract

We theoretically analyse the dynamics of a suspended graphene membrane which is in tunnel contact with grounded metallic electrodes and subjected to ac-electrostatic potential induced by a gate electrode. It is shown that for such system the retardation effects in the electronic subsystem generate an effective pumping for the relatively slow mechanical vibrations if the driving frequency exceeds the inverse charge relax- ation time. Under this condition there is a critical value of the driving voltage ampli- tude above which the pumping overcomes the intrinsic damping of the mechanical resonator leading to a mechanical instability. This nonresonant instability is saturated by nonlinear damping and the system exhibits self-sustained oscillations of relatively large amplitude.