Tunable the spin Hall effect of light with graphene metamaterial

Abstract

The spin Hall effect of light (SHEL) is a transport phenomenon which shows a small spatial shift perpendicular to the refractive index gradient for a linearly polarized light passing through an interface. In this paper, we have demonstrated a three-layer structure (glass–graphene metamaterial–air) to explore the characteristics of the spin Hall effect of reflected light at the glass–graphene metamaterial interface. The effects of temperature and Fermi energy of graphene and the thickness of graphene metamaterial on the horizontal and vertical displacements of SHEL are calculated and discussed. The results show that the behavior of SHEL is very slightly temperature dependent at higher wavelength while Fermi energy has significantly changed it. We also find that the thickness of graphene metamaterial has greatly modified the horizontal beam shifts, but has slightly influence on the vertical beam shifts. Moreover, different Fermi energy lead to two dispersion regions, elliptic and hyperbolic cases. The behavior of SHEL behave differently in these two cases and can be tuned by chemical doping or gate voltage. We may find a tunable way to enhance or weaken the behavior of SHEL with our will by using the proposed simple three-layer structure.