Tunable spin hall effect via hybrid polaritons around epsilon-near-zero on graphene-hBN heterostructures

We present a tunable spin Hall effect of light (SHEL) by introducing a monolayer of graphene on the hexagonal boron nitride (hBN). The interaction between the phonon polaritons in hBN and the plasmon polaritons in graphene can significantly enhance the SHEL around epsilon-near-zero (ENZ) near reststrahlen band-I (RB-I) in a very wide range of incident angles and compress it obviously in reststrahlen band-II (RB-II). The spin shifts can be obtained by adjusting the ratio of reflective coefficient and the phase difference for s- and p-waves which can be easily manipulated by the chemical potential. The effect of the tilted angle, thickness of hBN and incident angle on the SHEL is also discussed. These findings may lead to the potential applications for the nano-optical device based on the spin optics and the control of photons.