Spin current induced by in-plane magnetoelectric δ-barriers in a two-dimensional electron gas

Abstract

We model the ballistic spin current within a two-dimensional electron gas (2DEG) under the influence of magnetoelectric barriers and Rashba spin-orbit coupling. The magnetic field By is applied in the 2DEG in-plane direction rather than in the perpendicular direction Bz, as considered previously. The use of an in-plane field induces a spin current which is more resistant to the D'yakonov type of spin relaxation. It is shown theoretically that the electron energy dispersion is independent of the magnetic vector potential arising from in-plane fields. This enables electron conduction to maintain high conductance, even when multiple barriers are used to enhance the spin polarization of current. The polarization of current is also derived as a function of the Rashba spin-orbit coupling strength, the electric potential, and the magnetic field strength. The magnitude and direction of spin polarization can be modulated externally by a By field, which is useful for spintronics applications. © 2005 The American Physical Society.