Spin polarization of electrons by non-magnetic heterostructures : basics   of spin-optics
  We propose to use the lateral interface between two regions with different strengths of the spin-orbit interaction(s) to spin-polarize the electrons in gated two dimensional semiconductor heterostructures. For a beam with a non zero angle of incidence the transmitted electrons will split into two spin polarization components propagating at different angles. We analyze the refraction at such an interface and outline the basic schemes for filtration and control of the electron spin. 
M. Khodas, A. Shekhter and A.M. Finkel'stein