Spin-orbit-coupling induced electron-spin polarization in magnetically and electrically confined semiconductor microstructure

We theoretically investigate spin polarization for electrons in magnetically and electrically confined semiconductor microstructure, which is constructed by patterning a ferromagnetic stripe and a Schottky-metal stripe on top and bottom of GaAs/AlxGa1-xAs heterostructure, respectively. Both Zeeman interaction and spin–orbit coupling are taken into account; however, electron-spin polarization comes mainly from the latter due to a small effective g-factor for GaAs. Besides, both magnitude and sign of spin polarization can be manipulated by changing interfacial confining electric field or strain engineering, resulting in a tunable electron-spin filter for spintronics device applications.