Negative nonlinear damping of a graphene mechanical resonator

TL;DR

This study explores the nonlinear behavior of a multilayer graphene resonator, revealing negative nonlinear damping and new instabilities through optomechanical measurements, advancing understanding of graphene's mechanical properties.

Contribution

The paper experimentally demonstrates negative nonlinear damping in a graphene resonator and identifies nonlinear regimes beyond Duffing behavior using optomechanical techniques.

Findings

Observation of negative nonlinear damping at large amplitudes

Identification of nonlinear regimes with new mechanical instabilities

Quantification of mechanical Duffing nonlinearity in graphene

Abstract

We experimentally investigate the nonlinear response of a multilayer graphene resonator using a superconducting microwave cavity to detect its motion. The radiation pressure force is used to drive the mechanical resonator in an optomechanically induced transparency configuration. By varying the amplitudes of drive and probe tones, the mechanical resonator can be brought into a nonlinear limit. Using the calibration of the optomechanical coupling, we quantify the mechanical Duffing nonlinearity. By increasing the drive force, we observe a decrease in the mechanical dissipation rate at large amplitudes, suggesting a negative nonlinear damping mechanism in the graphene resonator. Increasing the optomechanical backaction, we observe a nonlinear regime not described by a Duffing response that includes new instabilities of the mechanical response.