Spin polarization control in two dimensional electron systems: enhanced Zeeman splitting and spin-orbit interaction effects

We investigate the spin-dependent transport prop-erties of two-dimensional electron gas (2DEG) systems formed in diluted magnetic semiconductors that also have Rashba spin-orbit interaction. We focus on nanostructures consisting of realistic magnetic barriers produced by the deposition of ferromagnetic stripes on heterostructures. We show that the quantum transmission in a given barrier system depends greatly on the magnetization pattern of the stripes, the injected spin direction, the strength of the spin-orbit coupling, and the enhanced Zeeman splitting effect in the diluted magnetic semiconductor. It is shown that significant spin polarization can be obtained by properly fabricating the ferromagnetic stripes and adjusting their separation from the 2DEG. The polarization function can also be controlled by the application of external magnetic fields.