Quantum estimation of coupling strengths in driven-dissipative optomechanics

TL;DR

This paper uses local quantum estimation theory to analyze how well one can measure linear and quadratic coupling strengths in a driven-dissipative optomechanical system, highlighting the ease of estimating linear coupling and the role of temperature.

Contribution

It introduces a quantum estimation framework for optomechanical coupling parameters, showing the mechanical element's state contains most information and that position measurements are nearly optimal.

Findings

Linear coupling is easier to estimate than quadratic.

Mechanical position quadrature measurement is nearly optimal.

Temperature effects are more significant for quadratic coupling.

Abstract

We exploit local quantum estimation theory to investigate the measurement of linear and quadratic coupling strengths in a driven-dissipative optomechanical system. For experimentally realistic values of the model parameters, we find that the linear coupling strength is considerably easier to estimate than the quadratic one. Our analysis also reveals that the majority of information about these parameters is encoded in the reduced state of the mechanical element, and that the best estimation strategy for both coupling parameters is well approximated by a direct measurement of the mechanical position quadrature. Interestingly, we also show that temperature does not always have a detrimental effect on the estimation precision, and that the effects of temperature are more pronounced in the case of the quadratic coupling parameter.