Quantum correlation enhanced weak field detection in optomechanical system.

We propose a theoretical scheme to enhance the signal-to-noise ratio in ultrasensitive detection with the help of quantum correlation. By introducing the auxiliary oscillator and treated as an added probe for weak field detection, the additional noise can be greatly suppressed and the measurement accuracy may even break the standard quantum limit. We use the magnetic field as an example to exhibit the detection capability of our scheme. The result show that, comparing with the traditional detection protocol, our scheme can have higher signal-to-noise ratio and better detection accuracy. Furthermore, the signal intensity detection curve shows a good linearity. Our results provide a promising platform for reducing the additional noise by utilizing quantum correlation in ultrasensitive detection.