Rashba自旋-轨道相互作用影响下量子盘中强耦合磁极化子性质的研究  

Study of the properties of strong-coupling magnetopolaron in quantum disks induced by the Rashba spin-orbit interaction

作　　者：白旭芳[1] 乌云其木格[1] 辛伟[2] 额尔敦朝鲁[2] 

机构地区：[1]内蒙古民族大学物理与电子信息学院,通辽028043 [2]河北科技师范学院物理系,秦皇岛066004

出　　处：《物理学报》2014年第17期321-328,共8页Acta Physica Sinica

基　　金：河北省自然科学基金(批准号:E2013407119);河北省高等院校科学技术研究重点项目(批准号:ZD20131008);内蒙古自治区高等学校科学研究项目(批准号:NJZY14189)资助的课题~~

摘　　要：本文基于Lee-Low-Pines幺正变换法,采用Tokuda改进的线性组合算符法研究了Rashba自旋-轨道相互作用效应下量子盘中强耦合磁极化子的性质.结果表明,磁极化子的相互作用能Eint的取值随量子盘横向受限强度ω0、外磁场的回旋频率ωc、电子-LO声子耦合强度α和量子盘厚度L的变化均与磁极化子的状态性质密切相关;磁极化子的平均声子数N随ωc,ω0和α的增加而增大,随L的增加而振荡减小;在Rashba自旋-轨道相互作用效应影响下磁极化子的有效质量将劈裂为m*+,m*-两种,它们随ωc,ω0和α的增加而增大,随L的增加而振荡减小;在研究量子盘中磁极化子问题时,电子-LO声子耦合和Rashba自旋-轨道相互作用效应的影响不可忽略,但Rashba自旋-轨道相互作用和极化子效应对磁极化子的影响只有在电子运动的速率较慢时显著.On the basis of Lee-Low-Pines unitary transformation, the properties of strong-coupling magnetopolarons in quantum disks （QDs） induced by the Rashba spin-orbit interaction are studied using the Tokuda improved linearly combined operator method. Results show that the state properties of magnetopolarons are closely linked with the sign of the interaction energy Eint, and the Eint of magnetopolarons changes with the transverse confinement strength ω0, the cyclotron frequency of the external magnetic field wc, the electron-LO phonon coupling strength α, and the thickness L of QDs. The average number N- of phonons increases with increasing we, ω0 and α, but the oscillation decreases with increasing thickness L of QDs. The effective mass m0 of magnetopolarons splits into two （m＋ and m-）, induced by the Rashba spin-orbit interaction, and the values of them increase with increasing ωc, ω0 and α, but the oscillation decreases with increasing thickness L of QDs. For the ground state of magnetopolarons in QDs, the electron-LO phonon interaction plays a significant role, meanwhile, the Rashba spin-orbit coupling effect cannot be ignored. Only for the lower volocity of the electrons, can the polaron effect and the Rashba spin-orbit interaction effect on the magnetopolaron be obvious.

关 键 词：量子盘 Rashba自旋-轨道相互作用 磁极化子 相互作用能 

分 类 号：O469[理学—凝聚态物理]