Magnetic field measurement in a hybrid microwave optomechanical-magnetic coupled system

This paper proposes a magnetic field measurement scheme based on a hybrid microwave optomechanical-magnetic coupled system. The proposed sensor comprises a yttrium iron garnet sphere and an optomechanical cavity, where the spring coefficient of the cavity is parametrically modulated. The results demonstrate that the system’s response to the input signal is significantly enhanced, amplifying the weak input signal while reducing the added noise of measurement below the standard quantum limit. Consequently, this hybrid system serves as an effective amplifier, generating a stronger output signal while maintaining sensitivity nearly identical to that of the bare system. We posit that these findings may offer an efficient method for magnetic field measurement and contribute to the advancement of technology in quantum precision measurements.