通过嵌入铁磁电极之间Aharonov-Bohm干涉仪自旋极化输运性质的研究  

Spin-dependent transport through a closed Aharonov-Bohm interferometer coupled to ferromagnetic electrodes

作　　者：吴绍全[1] 

机构地区：[1]四川师范大学物理与电子工程学院,成都610068

出　　处：《物理学报》2009年第6期4175-4182,共8页Acta Physica Sinica

基　　金：四川省应用基础研究基金(批准号:2006J13-155);四川省教育厅自然科学研究基金(批准号:2006A069)资助的课题~~

摘　　要：使用非平衡态格林函数方法和运动方程近似,研究了嵌入铁磁电极之间Aharonov-Bohm干涉仪的自旋极化输运性质.在左右铁磁电极平行和反平行两种磁组态下,结合Fano因子分析和讨论了Fano和Kondo共振对该系统电导的影响,以及电导随自旋极化强度和磁通的变化.结果表明,自旋极化强度和磁通能有效地调节和控制电导,但电导的线形主要由磁通决定;在适当的条件下能导致大的正磁阻和负磁阻的出现.因此,该系统是一个很好的自旋阀晶体管,在自旋电子学中有潜在的应用价值.Using the Keldysh nonequilibrium Green function and equation-of-motion technique, we investigate the spin-dependent transport through a closed Aharonov-Bohm intefferometer coupled to ferromagnetic leads. With the Fano factor, We analyse the effect of the Fano and the Kondo resonance on the conductance and the variation of the conductance with the spin-polarization strength and the magnetic flux in both the parallel and the antiparallel lead-polarization alignments. Our results show that the conductance can be controlled effectively by the spin-polarization strength and the magnetic flux, while the line shapes of the conductance depend mainly on the magnetic flux and that a large tunneling magnetoresistance and a negative tunneling magnetoresistance can arise by adjusting the relative parameters. This system is a possible candidate for spin valve transistors and is of potential applications in the spintronics.

关 键 词：Fano和Kondo共振 自旋极化强度 Fano因子 隧道磁阻 

分 类 号：O469[理学—凝聚态物理]