Spin filtering in single magnetic barrier structures revisited

We reexamine spin-dependent transport properties of two-dimensional electrons modulated by the stray field of a ferromagnetic metal (FM) stripe on top. When the magnetization is along the transport direction of the electrons, the FM stripe generates not only a magnetic barrier but also an in-plane magnetic field component. Previous studies have omitted the in-plane magnetic field component and shown that such a device does not possess any spin-filtering effect. We show that with inclusion of this in-plane magnetic field component, a spin polarization of nearly 100% can be achieved in such a single FM-stripe modulated two-dimensional electron gas device.