Sensitive sensing based on quantum correlation of photons in weak nonlinear regime

Quantum correlation of photons based on quantum interference, such as unconventional photon blockade (UPB), has been extensively studied for realizing single-photon sources in a weak nonlinear regime. However, how to use this effect for other practical applications is rarely studied. Here, we propose to realize angular velocity and temperature sensing based on the quantum correlation of photons induced by quantum interference. We demonstrate that UPB can be observed in the mixing field output from a Mach–Zehnder interferometer (MZI) with two cavities in its two arms based on quantum interference. We show that the second-order correlation function of the output field is sensitive to the parameters of the system, and propose schemes to realize angular velocity and temperature sensing by measuring the second-order correlation of the photons output from the MZI. We find that the second-order correlation function of the output field is much more sensitive to the parameters of the system than the mean photon number, which provides an application scenario for UPB in sensitive sensing.