Microwave‐Controlled Photonic Spin Hall Effect in Atomic System and Microwave Electrometry

ABSTRACT The photonic Spin Hall Effect (SHE) causes a polarization‐dependent transverse shift of light at an interface. In this paper, we theoretically investigate the microwave‐controlled photonic SHE and microwave electrometry in a closed‐loop ‐type atomic system. At zero probe detuning () and relative phase , the photonic SHE magnitude remains at the intrinsic finite‐beam saturation limit , whereas the microwave field shifts its angular position linearly with opposite slopes (signs) for the two phases, enabling differential microwave electric‐field sensing. At , the photonic SHE magnitude decays exponentially with , providing weak microwave electric field sensing. In contrast, at (control field coupling), the photonic SHE reaches a maximum of half the incident beam waist when and the phase is optimized. Interestingly, we observed microwave‐controlled switching of photonic SHE by tuning the relative phase at an optimized value of and . Our results may have potential applications in microwave quantum sensing and quantum optical switches based on the photonic SHE.