Rashba spin-orbit interaction induced spin-polarized Andreev-reflection current through a double Aharonov-Bohm interferometer

Using the standard nonequilibrium Green's function techniques, we investigate the spin-polarization dependent Andrecv-reflcction currents through a double Aharonov-Bohm interferometer with Rashba spin-orbit interaction. It is demonstrated that the spin polarization is induced by the Rashba spin-orbit interaction, which results in a phase difference between two quantum dots of the interferometer. The spin polarization of currents can be adjusted by tuning the Rashba spin-orbit interaction strength, the magnetic flux, and the interdot coupling as well, which lead to the transport current of complete spin polarization (either spin up or down) in both cases, with or without the interdot coupling. However, the current of complete spin polarization can approach its maximum value only in the absence of the interdot coupling. (C) 2008 American Institute of Physics.