多层结构双自旋过滤隧道结中的电子输运特性

在转移矩阵方法及Mireles和Kirczenow的量子相干输运理论的基础上，研究了正常金属层/磁性半导体层/非磁绝缘层/磁性半导体层/正常金属层型双自旋过滤隧道结中Rashba自旋轨道耦合效应和自旋过滤效应对自旋相关输运的影响.讨论了隧穿磁电阻（TMR）、隧穿电导与各材料层厚度、Rashba自旋轨道耦合强度以及两磁性半导体中磁矩的相对夹角θ之间的关系.研究表明：含磁性半导体层的双自旋过滤隧道结由于磁性半导体层的自旋过滤效应和Rashba自旋轨道耦合作用可获得极大的TMR值.另外TMR和隧穿电导随着Rashba自旋轨道耦合强度的变化而振荡，振荡周期随Rashba自旋轨道耦合强度的增大逐渐减小. 关键词： 双自旋过滤隧道结 Rashba自旋轨道耦合 隧穿磁电阻 隧穿电导

Electronic transport properties of the multilayer structure double spin-filter tunnel junction

Based on the transfer matrix method and the quantum coherent transport theory of Mireles and Kirczenow, the effects of the Rashba spin-orbit coupling and the spin-filter on the electronic transport properties in the NM/FS1/I/FS2/NM(NM represents the nonmagnetic metal layer, I represents the nonmagnetic insulator layer, and FS represents the magnetic semiconductor layer) double spin-filter tunnel junction are investigated. The influence of thickness of insulator layer and magnetic semiconductor layer on the tunnel magnetoresistance (TMR) and conductance are studied for different Rashba spin-orbit coupling strength and the different angle θ between the two magnetic moments of the left and right magnetic semiconductor layer. The results indicate that: in the presence of the spin-filter effect and the Rashba spin-orbit coupling interaction in the magnetic semiconductor layer, large TMR can be obtained in this double spin-filter junction. With the strength of Rashba spin-orbit coupling increasing, the tunnel magnetoresistance and conductance exhibit rapidly oscillating behavior and the oscillation period decreases gradually.