Quantum Magnetometer with Dual‐Coupling Optomechanics

An experimentally feasible magnetometer based on a dual-coupling optomechanical system is proposed, where the radiation-pressure coupling transduces magnetic signal to optical phase, and quadratic interaction induces periodic squeezing effect. The latter not only amplifies be measured, but also accelerates transducing rate characterized by an observable phase accumulation efficiency. In vicinity of opto-mechanical decoupled time, ultimate bound estimability proportional $\exp(-6r)$, then optimized accuracy estimation can enhanced nearly 3 orders with controllable parameter $r<1$. Moreover, our proposal robust against mechanical thermal noise, sensitivity specific measurement reach order $10^{-17}{\rm T/\sqrt{Hz}}$ in presence dissipations without ground state cooling oscillator. Our fundamentally broadens fields quantum metrology cavity optomechanics, potential application for on-chip detection high precision.