Spin filtering by depositing hybrid ferromagnetic nanosized stripes on a semiconductor heterostructure

Spin filter devices based on resonant tunneling hybrid magnetic-barrier structures are proposed and spin-dependent transport properties are investigated theoretically. Such a kind of devices can be experimentally realized by depositing two ferromagnetic stripes with different magnetizations on top of two-dimensional electron gas contained in a semiconductor heterostructure. Since these two ferromagnetic stripes induce different magnetic barriers, which leads to the strong dependence of both electronic transmission probability and conductance of device on electronic spins, electrons show up a considerable spin polarization effect. These interesting properties may provide an alternative approach to spin-polarize electrons in semiconductors and may be used as spin filters.