Tunneling induced giant Photonic Spin Hall effect in quantum wells

Abstract: We propose a theoretical investigation of the photonic spin Hall effect (PSHE) in a mid-infrared probe field by employing an asymmetric double AlGaAsGaAs quantum well as the intracavity medium. The system is designed such that an external control beam together with tunable tunneling barriers regulates the quantum interference of the probe tunneling process. This configuration enables precise manipulation of the PSHE for both horizontally and vertically polarized components of light. Our analysis reveals the emergence of a giant horizontal PSHE in the quantum well based cavity system. Moreover, by incorporating absorptive and gain-assisted cavity slabs, the horizontal PSHE is further amplified, leading to an even more pronounced photonic spin separation. The results provide novel insights into light matter interactions in semiconductor quantum wells and suggest an effective route for enhancing and controlling the PSHE in mid-infrared photonic devices.