摘要
提出了含δ势垒的多臂量子环模型.研究发现总磁通为零时,持续电流随半导体环增大发生非周期性振荡,下臂因含δ势垒而获得最小的平均持续电流.AB磁通增强时,持续电流会发生周期性等幅振荡,并与电极的磁矩方向以及隧穿电子的自旋方向相关.两电极磁矩方向平行时,Rashba自旋轨道耦合具有改变持续电流相位和相位差的效应;两电极磁矩方向反平行时,Rashba自旋轨道耦合具有改变持续电流振幅的效应.各臂之间持续电流的不同与臂长和磁通分布的差异相关.在一定条件下,两种波函数所对应的持续电流是可分离的.
A new model of quantum ring with multiple arms containing δ barrier is proposed in this paper.The results imply that the persistent current shows behavior of nonperiodic oscillation with the size of the semiconductor ring increasing when the total magnetic flux is zero.The lower arm obtains minimal average persistent current because it contains the δ barrier.The persistent current generates periodic oscillation when the AB magnetic flux strengthens.It is related to not only the electrodes＇magnetic moment direction but also the tunneling electrons＇spin orientation.Furthermore,when the two magnetic moments are parallel,the Rashba spin-orbit interaction has the effect of changing the persistent current＇s phase and phase difference.However,when the magnetic moments in the two electrodes are antiparallel,the Rashba spin-orbit interaction affects the amplitude of the persistent current.Our results also indicate that the difference of the persistent current in each arm is retated to the arm length and the magnetic flux＇s distribution.The persistent currents which the two kind of wave functions correspond to are separated under definite conditions.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第4期2767-2774,共8页
Acta Physica Sinica
基金
河北省教育厅自然科学研究指导计划(批准编号:Z2008103)资助的课题~~
关键词
多臂量子环
持续电流
δ势垒
RASHBA自旋轨道耦合
quantum ring with multiple arms
persistent current
δ barrier
Rashba spin-orbit interaction
作者简介
E—mail：808dujian@163．com
