Photonic spin Hall effect in metasurfaces with rotational   symmetry-breaking
  Observation of photonic spin Hall effect (SHE) in dielectric-based metasurfaces with rotational symmetry breaking is presented. We find that the spin-dependent splitting is a unique angular splitting in the real position space, and is attributed to the space-variant Pancharatnam-Berry phase (PB). Breaking the rotational symmetry of the PB phase by misalignment of the central axes of the incident beam and the metasurface, the spin-dependent shift is observable. We show that the spin-dependent shift can be enhanced by increasing the rotation rate of the metasurface, so the metasurface provides a great flexibility in the manipulation of photonic SHE. 
Yachao Liu, Xiaohui Ling, Xunong Yi, Xinxing Zhou, Shizhen Chen,   Yougang Ke, Hailu Luo, and Shuangchun Wen
physics.optics