Optical spin-sensitive Zitterbewegung in bianisotropic metamaterials.

We present a theoretical analysis on optical spin-sensitive Zitterbewegung (ZB) in metamaterials. By developing some formulas about the dispersions and eigenstates of optical modes we show that spin-sensitive ZB can be obtained in a bianisotropic metamaterial with a proper coupling between the electric and magnetic responses. A close analogue of the developed analytical results with these of Dirac equation is proposed. Numerical simulation proves the existence of ZB on the refracted optical beam along a direction determined by the optical spin of incidence. Furthermore, we show that when the incident optical field is linearly polarized, although ZB on field intensity does not exist, the optical spin possesses an interesting spatial split and trembling phenomena. Significance of this investigation is discussed.