Diverged photonic spin hall effect in Weyl Photonic metamaterial

Weyl semimetal is gaining increasing attention due to the unprecedented physical observables including the chiral magnetoresistance effect in condensed physics matter. In optics however, observables besides the detection of Weyl node and the Fermi arcs are still in lack. In this work, we discover that when circularly polarized beams are reflected by a Weyl medium, a handedness dependent spin hall effect can be realized due to the topological properties of the scattering matrix arises from the Weyl node. The scattering properties of the Weyl node could dramatically influence the trajectory of the light in real space resulting in a handedness dependent Imbert-Fedorov shift. More importantly, the shift is shown to be diverging in approximate to the Weyl node. Our discovery creates a whole new and readily available platform realizing diverged spin hall effect of optical Weyl medium.