铁磁/半导体/铁磁结构的双量子环自旋输运的特性  

Properties of spin transport of double quantum rings with structures of ferromagnet/semiconductor/ferromagnet

作　　者：杜坚 李春光 秦芳 

机构地区：[1]承德高等民族师范专科学校物理系,承德067000

出　　处：《物理学报》2009年第5期3448-3455,共8页Acta Physica Sinica

基　　金：河北省教育厅自然科学研究指导项目(批准号:Z2008103)资助的课题~~

摘　　要：研究了与铁磁/半导体/铁磁结构相关的双量子环自旋输运的规律,研究结果表明:总磁通为零条件下,铁磁电极磁化方向反平行时,双量子环与单量子环相比提高了自旋电子透射概率的平均值.铁磁电极磁化方向平行时,双量子环对提高自旋向下电子平均透射概率的效果更明显;双量子环受到Rashba自旋轨道耦合作用影响时,自旋电子的平均透射概率明显高于单量子环,即使再加上外加磁场的影响,透射概率较高这一特征依然存在;双量子环所含的δ势垒具有阻碍自旋电子输运的作用,随δ势垒强度Z的增大透射概率将会单调、非线性地减小.Spin-dependent transport through ferromagnetic/semiconductor/ferromagnetic double quantum rings is studied in this paper. It is found that the average value of the spin-dependent electron transmission coefficient of the double quantum ring is larger than that of the single quantum ring under the condition of zero magnetic flux and antiparallel configration of the ferromagnetic electrodes. When the magnetization directions of the ferromagnetic electrodes are parallel, the average tunneling coefficient of the spin-down electrons in double quantum rings increases distinctly. When the Rashba spin-orbit coupling is considered, the average tunneling coefficient of the spin electrons in double quantum rings is bigger than that in single quantum ring. The applied magnetic field enhences the tunneling coefficient. The δ barrier of the double quantum rings suspresses the tunneling of the electron. The tunneling coefficient decreases monotonically and nonlinearly with the δ barrier strength Z increasing.

关 键 词：双量子环 RASHBA自旋轨道耦合 透射概率 δ势垒 

分 类 号：O471.1[理学—半导体物理]