Mesoscopic Stern-Gerlach spin filter by nonuniform spin-orbit   interaction
  A novel spin filtering in two-dimensional electron system with nonuniform spin-orbit interactions (SOI) is theoretically studied. The strength of SOI is modulated perpendicular to the charge current. A spatial gradient of effective magnetic field due to the nonuniform SOI causes the Stern-Gerlach type spin separation. The direction of the polarization is perpendicular to the current and parallel to the spatial gradient. Almost 100 % spin polarization can be realized even without applying any external magnetic fields and without attaching ferromagnetic contacts. The spin polarization persists even in the presence of randomness. 
Jun-ichiro Ohe, Masayuki Yamamoto, Tomi Ohtsuki and Junsaku Nitta