Squeezing-enhanced measurement sensitivity in a cavity optomechanical system

TL;DR

This paper theoretically analyzes how squeezing can improve measurement sensitivity in cavity optomechanical systems, finding significant benefits in the resolved sideband regime but limited gains in the unresolved regime.

Contribution

It provides a comparative analysis of measurement sensitivities using coherent and quantum-enhanced probing in cavity optomechanics, highlighting conditions for optimal squeezing benefits.

Findings

Quantum-enhanced probing offers limited improvement in the unresolved sideband regime.

Significant sensitivity improvements are possible with quantum squeezing in the resolved sideband regime.

Theoretical limits to squeezing-enhanced measurement sensitivity are established.

Abstract

We determine the theoretical limits to squeezing-enhanced measurement sensitivity of mechanical motion in a cavity optomechanical system. The motion of a mechanical resonator is transduced onto quadrature fluctuations of a cavity optical field and a measurement is performed on the optical field exiting the cavity. We compare measurement sensitivities obtained with coherent probing and quantum-enhanced probing of the mechanical motion, i.e. the coherent probe field carries vacuum states and quadrature squeezed vacuum states at sideband frequencies, respectively. We find that quantum-enhanced probing provides little to no improvement in motion sensing for resonators in the unresolved sideband regime but may significantly increase measurement sensitivities for resonators in the resolved sideband regime.