Nonlocal Nonlinear Control of Photonic Spin Hall Effect in Strongly Interacting Rydberg Media

Abstract

We present a theoretical study demonstrating enhanced tunability of the photonic spin Hall effect (PSHE) using a strongly interacting Rydberg atomic medium under electromagnetically induced transparency (EIT) conditions. In contrast to conventional approaches that rely on static refractiveindex profiles or metamaterials, here the PSHE is controlled via a nonlocal third-order nonlinear susceptibility arising from long range Rydberg-Rydberg interactions. We show that this nonlocal nonlinearity enables dynamic modulation of spin-dependent light trajectories, amplifying the normally weak PSHE into a readily observable and adjustable effect. These results pave the way for new capabilities in photonic information processing and sensing. In particular, an adjustable PSHE may enable beam steering based on photon spin, improve the sensitivity of precision measurements, and support photonic devices whose functionality can be reconfigured in real time.