Mechanical squeezing via unstable dynamics in a microcavity

TL;DR

This paper proposes a method to rapidly generate strong mechanical quantum squeezing in optomechanical systems by exploiting dynamical instability in the far red-detuned and ultrastrong coupling regime, especially suited for levitated nanoparticles.

Contribution

It introduces a novel mechanism leveraging unstable multimode quantum dynamics to achieve significant mechanical squeezing in microcavities with potential for quantum sensing.

Findings

Mechanical squeezing of tens of decibels predicted

Rapid squeezing on microsecond timescale demonstrated

Feasibility for levitated nanoparticles in microcavities argued

Abstract

We theoretically show that strong mechanical quantum squeezing in a linear optomechanical system can be rapidly generated through the dynamical instability reached in the far red-detuned and ultrastrong coupling regime. We show that this mechanism, which harnesses unstable multimode quantum dynamics, is particularly suited to levitated optomechanics, and we argue for its feasibility for the case of a levitated nanoparticle coupled to a microcavity via coherent scattering. We predict that for sub-millimeter-sized cavities the particle motion, initially thermal and well above its ground state, becomes mechanically squeezed by tens of decibels on a microsecond timescale. Our results bring forth optical microcavities in the unresolved sideband regime as powerful mechanical squeezers for levitated nanoparticles, and hence as key tools for quantum-enhanced inertial and force sensing.