Spin separation via a three-terminal Aharonov-Bohm interferometers

We propose a three-terminal ring-type device which contains a single-level quantum dot (QD) to extract or separate the spin-up and the spin-down electrons that are injected into the QD from a middle lead, into the left and the right leads, respectively. This scheme is based on the Rashba spin-orbit interaction (RSOI) in the bridge between the left and the right leads and is free from magnetic field or magnetic material. We find that both the spin directions and the magnitude of the outflow currents in the left and the right leads can be tuned by the RSOI strength and the structure parameters. (c) 2008 American Institute of Physics.