含Rashba自旋轨道耦合效应的非均匀量子线的极化输运性质

摘要

The spin-polarized electron transport for a narrow-wide- narrow (NWN) quantum wire under the modulation of Rashba spin-orbit coupling (SOC) is investigated via the spin-resolved lattice Green function method. The influence of both the structure of the quantum wire and the interference between different pairs of subbands on the spin polarized electron transport is taken into account simultaneously. It is found that a very large vertical spin-polarized current can be generated by the SOC-induced effective magnetic field at the structure-induced Fano resonance. Furthermore, the magnitude of the spin polarization can be tuned by the Rashba SOC strength and structural parameters. Those results may provide an effective way to design a spin filter device without containing any magnetic materials or applying a magnetic field.%采用递归格林函数法研究了含Rashba自旋轨道耦合(spin-orbit coupling,SOC)的窄-宽-窄形量子线的自旋极化输运性质.同时考虑了体系的结构和不同Rashba子带的混合对电子输运性质的影响,结果表明当电子的入射能量处在结构引起的Fano共振点时,能在出射端电极得到极化率较大的自旋极化电流,而且其大小可由自旋轨道耦合强度及系统的结构参数共同调节.这些效应说明所研究的体系也许能用来设计自旋过滤器件.