The photonic spin Hall effect (PSHE), a typical manifestation of spin-orbit interactions of light, is characterized by a transverse shift δ of photons with opposite spins. Precise measurement of this shift advances spin-dependent technologies, including precision metrology and optical sensing. Previous schemes to enhance the typically small shifts ($\delta /\lambda <{10}^{-1}$, where $\lambda$ is the operation wavelength) are limited to narrow angular cones ($\mathrm{\Delta }\theta <1^{\circ }$). While some efforts have achieved a giant PSHE over either broad bands or wide angles, combining both advantages cannot realize. Here, we demonstrate an enhanced PSHE (δ/$\lambda >0.5$) simultaneously over a broad midinfrared band ($13\sim 20\mu \mathrm{m}$) and a wide angular width ($\mathrm{\Delta }\theta =21.7^{\circ }$) using doped indium arsenide (InAs) multilayer films with gradient epsilon-near-zero (ENZ). Though applying a moderate magnetic field, the ENZ property and material loss of the anisotropic InAs films excite leaky $p$-polarized electromagnetic modes under $p$ polarization waves incident, leading to high broadband absorption. This absorption significantly outweighs that of $s$ polarization waves (which lack leaky modes), causing strong polarization splitting. Notably, this splitting is insensitive to incident angle and layer thickness variations, yielding a highly robust, wide-angle PSHE. This mechanism can be generalized to other III-V semiconductors, magnetized metals, topological Weyl semimetals, and zero refractive index metasurfaces.

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• Magnetic anisotropy
• Magnetism
• Spin dynamics
• Surface states
• Spin
• S-matrix method in transport