Spin filtering in a magnetic barrier structure: in-plane spin orientation

We investigate ballistic spin transport in a two dimensional electron gas system through magnetic barriers of various geometries using the transfer matrix method. While most of the previous studies have focused on the effect of magnetic barriers perpendicular to the two dimensional electron gas plane, we concentrate on the case of magnetic barriers parallel to the plane. We show that resonant oscillation occurs in the transmission probability without electrostatic potential modulation which is an essential ingredient in the case of ordinary out-of-plane magnetic barriers. Transmission probability of the in-plane magnetic barrier structure changes drastically according to the number of barriers and also according to the electrostatic potential modulation applied in the magnetic barrier region. Using a hybrid model consisting of a superconductor, ferromagnets, and a two dimensional electron gas plane, we show that it can serve as a good in-plane oriented spin selector which can be operated thoroughly by electrical modulation without any magnetic control.