Decoherence Suppression by Cavity Optomechanical Cooling

TL;DR

This paper investigates how cavity optomechanical systems with nonlinearities can be used to suppress decoherence of mechanical resonators, finding that Kerr nonlinearities and nonlinear damping enable significant decoherence reduction.

Contribution

It demonstrates that nonlinear effects in cavity optomechanical systems can be exploited to effectively suppress decoherence, unlike linear response configurations.

Findings

Linear response yields no significant decoherence suppression.

Kerr nonlinearity reduces decoherence rate substantially.

Nonlinear damping further enhances decoherence suppression.

Abstract

We consider a cavity optomechanical cooling configuration consisting of a mechanical resonator (denoted as resonator b) and an electromagnetic resonator (denoted as resonator a), which are coupled in such a way that the effective resonance frequency of resonator a depends linearly on the displacement of resonator b. We study whether back-reaction effects in such a configuration can be efficiently employed for suppression of decoherence. To that end, we consider the case where the mechanical resonator is prepared in a superposition of two coherent states and evaluate the rate of decoherence. We find that no significant suppression of decoherence is achievable when resonator a is assumed to have a linear response. On the other hand, when resonator a exhibits Kerr nonlinearity and/or nonlinear damping the decoherence rate can be made much smaller than the equilibrium value provided that the parameters that characterize these nonlinearities can be tuned close to some specified optimum values.