Coherent- and dissipative-coupling control of photonic spin hall effect in cavity magnomechanical system

Abstract

Non-Hermitian systems with dissipative magnon–photon coupling present fascinating physics that extends beyond conventional Hermitian systems. We propose a theoretical approach to investigate the photonic spin Hall effect (PSHE) in a non-Hermitian cavity magnomechanical (CMM) system utilizing a yttrium iron garnet (YIG) sphere placed inside the microcavity. Controlling the angular position of the YIG sphere can result in coherent and dissipative magnon–photon coupling. In these coupling instances, we investigate the dynamical manipulation of the PSHE and emphasize the significance of exceptional points (EPs) in enhancing spin-dependent shifts. We utilize the transfer matrix approach to compute the ratio of reflection coefficients for the TE- and TM-components, demonstrating the manipulation of the transverse shift of reflected light from positive to negative around the Brewster angle. Our results demonstrate that the CMM system, particularly in the dissipative coupling instance, has substantially higher PSHE shifts than the CM system, illustrating the impact of both dissipative coupling and the incorporation of a mechanical mode on spin-photonic interactions. Our work sheds light on EP-assisted CMM setups, which open up a novel avenue for dynamically manipulating photonic spin effects with broader implications in spin-based photonic devices.