特殊结构的多臂量子环的持续电流

提出了中臂弯曲的多臂量子环模型，且是上臂最短和下臂最长的不等臂量子环.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，并与电极的磁矩方向及隧穿电子的自旋方向相关，下臂因为最长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振荡，各臂之间明显出现相互制约的现象.各臂持续电流之间的差异与臂长和磁通分布相关，Rashba自旋轨道耦合具有改变持续电流相位和相位差的效应.在一定条件下，两种波函数所对应的持续电流是可分离的.关键词：多臂量子环持续电流Rashba自旋轨道耦合

Persistent spin current properties in a special structure of quantum ring with multiple arms

A new model of quantum ring with multiple arms whose middle arm is curved was proposed in this article.This is an unequal arm quantum ring with a shortest upper arm and a longest lower arm.The results indicate that the persistent spin current shows nonperiodic vibration with the size of the semiconductor ring increasing when the total magnetic flux is zero.And it is related to the electrodes'magnetic moment direction as well as the tunneling electrons'spin orientation.The average persistent spin current in the lower arm is minimum on account of its longest length.When the AB magnetic flux strengthens,the persistent spin current in each arm generates periodic oscillation and shows mutual restriction.The difference in each arm is related to the arm length and the magnetic flux distribution.Furthermore,the Rashba spin-orbit interaction affects the phase and the phase difference of the persistent spin current.Our results also imply that the persistent spin currents which the two kind of wave functions correspond to are separated under definite conditions.