摘要

The electron spin polarization in two quantum dots, which are inserted in one arm of a mesoscopic ring, is investigated by means of the non-equilibrium Keldysh Green's function technique. We find that the spin accumulations in the two dots Delta n(i) = n(i up arrow) - n(i down arrow), where n(i sigma) is the spin-sigma electron occupation number in dot i, can be efficiently tuned in terms of the applied bias voltage V, the interdot tunneling coupling strength t(C) and the phase induced by Rashba spin-orbit interaction. By adjusting these parameters, Delta n(1) and Delta n(2) can be generated and manipulated either simultaneously or separately, which may have real usage in spintronics or quantum information devices. We interpret the origin of the spin accumulation in terms of the spin-dependent total effective coupling strengths between the leads and the dots.

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