分子量子点中声子辅助的Kondo效应  

Influence of Electron-phonon Interaction on Kondo Effect

作　　者：于慧[1] 梁九卿[2] 

机构地区：[1]中北大学理学院物理系,山西太原030051 [2]山西大学理论物理研究所,山西太原030006

出　　处：《山西大学学报（自然科学版）》2010年第2期207-214,共8页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(10475053;10525418)

摘　　要：利用Keldysh非平衡格林函数方法讨论了与铁磁电极相连的单分子晶体管在强电子关联和电声子耦合共同作用下的量子输运特性.研究发现,当铁磁电极处于平行磁化位形时,会呈现出与反平行位形明显不同的输运行为.尤为显著的是,声子效应导致隧穿磁阻TMR随偏压在正负值间交替变化,这暗示了TMR是探索Kondo共振特征行为的一个更为有效的工具.Spin-polarized transport through single-molecule quantum dot with two ferromagnetic leads is investigated under the interplay of strong electron correlation and electron-phonon （e-ph） coupling. It is observed that the transport properties are distinctly different for the parallel magnetic configuration of electrodes in contrast to the antiparallel case. Furthermore,the tunnel magnetoresistance （TMR） alternates between the positive and the negative values along with the variation of polarization and bias voltage. The peculiar TMR line-shape observed here may serve as a more effective tool to explore the Kondo-resonance features in practical systems.

关 键 词：铁磁电极 电声子耦合 KONDO效应 隧穿磁阻 

分 类 号：O411[理学—理论物理]