Spin Hall effect of reflected light in dielectric magneto-optical thin film with a double-negative metamaterial substrate

Abstract

We study spin the Hall effect (SHE) of reflected light in a dielectric magneto-optical thin film of Ce1Y2Fe5O12 (Ce:YIG) with a double-negative (DNG) metamaterial substrate. The spin-dependent splitting expressions of left- and the right-handed circularly polarized (LHCP and RHCP) components in longitudinal, polar and transverse magneto-optical Kerr effect (MOKE) configurations are obtained. Meanwhile we first obtain the analytical expressions of the SHE shift of reflected light for three MOKE configurations by proper approximation. Owing to the enhancement of the MOKE by DNG metamaterial, the external magnetic field shows a large enhancement and modulation to spin-dependent splitting of reflected light. Based on simulation results, the influences of magnetic field direction and substrate material on the transverse centroid shifts of the reflected left- and right-handed circularly polarized light perpendicular to incident plane are analyzed. We find the maximum spin-dependent splitting between LHCP and RHCP components achieves about 9.2 μm and the maximum value of the magneto-optical spin Hall effect (MOSHE) shift reaches 9 μm in polar MOKE configuration. In order to make our results convincing we use a realizable DNG metamaterial with silver nanostructures as substrate to verify our conclusion. The DNG metamaterial provides a flexible method to manipulate and enhance SHE of light.