材料期刊网

Spin-dependent electron transport properties in a parallel double-quantum-dot structure with four terminals are theoretically investigated by means of the nonequilibrium Green function technique. When applying a local Rashba spin-orbit interaction on an individual quantum dot and introducing a finite bias between the transverse terminals, we show that in the presence of appropriate structure parameters, apparent pure spin currents come into being in the longitudinal terminals with the same amplitude and opposite polarization directions. Besides, the polarization directions of such spin currents can be efficiently inverted by the adjustment of structure parameters. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim