Magneto-Optical Spin Hall Effect Regulation at Terahertz Frequencies Based on Graphene–Gold Heterojunction

Abstract

In this paper, we theoretically consider the magneto-optical spin Hall effect of light (MOSHEL) in a graphene–gold heterojunction structure at terahertz frequencies, and determine the maximum value of the transverse shift of the spin Hall effect of light (SHEL) in the designed structure by varying the terahertz frequency, the thickness of the metal layer, the Fermi energy level of the graphene, and the magnetic induction density. When the terahertz frequency was 1.2 THz, the metal layer thickness 50 nm, the Fermi level 0.2 eV, and the magnetic induction density B was 10 T, the SHEL shifts of left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) components was greatest at the critical angle (58°), with as value of 498μm, 1000 times larger than the visible light. At this point, graphene exhibited a significant magneto-optical effect, dramatically enhancing the splitting extrema of LHCP and RHCP. This structure will provide possibilities for enhancement of the transverse shift and efficient regulation of the optical spin Hall effect within the terahertz range.