Analytical and experimental guide for axionlike particle search using biphotons.
This paper presents a cutting-edge optical system for detecting axion-like particles (ALPs) that employs the quantum entanglement of photon pairs created via a spontaneous parametric down-conversion (SPDC) and Primakoff process that converts photons into ALPs in the presence of a magnetic field. The laser beam from the source is first projected through a birefringent crystal where SPDC occurs, converting a single high-energy photon into a pair of low-energy photons. The photons in each pair then flow through a region with an applied magnetic field and eventually arrive at separate detectors known as photon counters. By examining the biphoton correlation using the probability distribution of the photons at the detectors, which varies according to the displacement of the main pump photon stream and the change in the number of photons due to the photon-to-axion conversion, the presence of ALPs can be determined. This optical setup enables detection of ALPs with low noise as well as remarkably high precision and sensitivity using quantum entanglement. The proposed technique provides an analytical model and system design for detecting ALPs.