Large photonic spin Hall effect in two dimensional semi-Dirac materials

Abstract

A strong photonic spin Hall effect (PSHE) in the absence of external magnetic field is important to control the spin states of photons and design next-generation photonic devices based on spinotpics. Herein, we theoretically study the PSHE on the surface of semi-Dirac materials. We established a general model, by changing various incident conditions, to describe the spin-orbit interaction of light in semi-Dirac materials. When we made these changes, we found that a large PSHE arises from the intrinsic anisotropy in the dispersion of semi-Dirac materials. The in-plane (transverse) spin Hall shift is dozens times of λ i , where λ i is the wavelength of the incident photon. Both of them can be effectively tuned by adjusting the optical axis angle and the photon energy. The maximum of the total in-plane and transverse spin Hall shift is 83.91λ i and 19.65λ i , respectively, which is larger than those in conventional anisotropic two-dimensional materials and isotropic Dirac materials. Our results shed light on the spin-orbit coupling of light in semi-Dirac materials and pave the way for designing spin-optical devices.