Quantum-correlation-enhanced weak-field detection in an optomechanical system

Abstract

A theoretical scheme is proposed to enhance the signal-to-noise ratio in ultrasensitive detection by quantum correlation in a composite optomechanical system. Introducing an auxiliary oscillator and treating it as an added probe for weak-field detection, the additional noise can be greatly suppressed, which may even break the standard quantum limit. A magnetic field is employed as an example to exhibit the detection capability of the scheme. The result shows that, compared with the traditional detection protocol, the scheme has a higher signal-to-noise ratio and a better detection accuracy. Furthermore, the signal intensity detection curve shows a good linearity. The results provide a promising platform for reducing the additional noise by utilizing quantum correlation in ultrasensitive detection.