Generation of spin polarization in two-terminal electron waveguides by spin-orbit interaction and magnetic field modulations

We discuss the possibility of generating spin polarization out of an unpolarized source in the single-channel regime of electron transport using a two-terminal quantum waveguide structure under Rashba spin-orbit interaction (SOI) and local magnetic field modulations. The SOI modulation alone cannot generate any spin filtering effect. When the magnetic modulation is included, finite polarization can be achieved. Within a broad region of the SOI strength and magnetic field amplitude a polarization of nearly 100% appears even without the Zeeman splitting.