对称抛物势阱磁性隧道结中的自旋输运及磁电阻效应  

Spin-polarized electron transport and magnetoresistance effect in symmetric parabolic-well magnetic tunneling junction

作　　者：刘德[1,2] 张红梅[3] 贾秀敏[3] 

机构地区：[1]河北师范大学物理科学与信息工程学院,石家庄050016 [2]河北省新型薄膜材料实验室,石家庄050016 [3]河北科技大学理学院,石家庄050018

出　　处：《物理学报》2011年第1期651-657,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10674040和10974043);河北师范大学博士基金(批准号:L2009B02);河北科技大学基金(批准号:XL200825)资助的课题~~

摘　　要：研究了两端具有铁磁接触的对称抛物势阱磁性隧道结(F/SPW/F)中自旋相关的隧穿概率和隧穿磁电阻,讨论了量子尺寸效应和Rashba自旋轨道耦合作用对自旋极化输运特性的影响.研究结果表明:隧穿概率和隧穿磁电阻随抛物势阱宽度的增加发生周期性的振荡.抛物势阱深度的增加减小了隧穿概率和隧穿磁电阻的振荡频率.Rashba自旋轨道耦合强度的增加加大了隧穿概率和隧穿磁电阻的振荡频率.隧穿概率和隧穿磁电阻的振幅和峰谷比强烈依赖于两铁磁电极中磁化方向的夹角.We investigated the spin-dependent transmission coefficient and tunneling magnetoresistance in symmetric parabolic-well with two ferromagnetic contacts （ F/SPW/F）. The quantum size effect and Rashba spin-orbit interaction are discussed simultaneously. The results indicate that the transmission coefficient and tunneling magnetoresistance are periodic function of the parabolic-well width. The oscillation frequencies of the transmission coefficient and tunneling magnetoresistance decrease with the increasing of the parabolic-well depth. The oscillation frequencies of the transmission coefficient and tunneling magnetoresistance increase with the increasing of the Rashba spin-orbit coupling strength. The amplitude and peak-to-valley ratio of the transmission coefficient and tunneling magnetoresistance are strongly dependent on the difference in orientations of the two magnetizations in the left and right ferromagnets.

关 键 词：磁性隧道结 RASHBA自旋轨道耦合 隧穿概率 隧穿磁电阻 

分 类 号：O472[理学—半导体物理]