Rashba自旋-轨道耦合调制的单层半导体纳米结构中电子的自旋极化效应  

Electron-spin polarization effect in Rashba spin-orbit coupling modulated single-layered semiconductor nanostructure

作　　者：贺亚萍 陈明霞[1] 潘杰锋 李冬 林港钧 黄新红 He Ya-Ping;Chen Ming-Xia;Pan Jie-Feng;Li Dong;Lin Gang-Jun;Huang Xin-Hong(Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学,桂林541004

出　　处：《物理学报》2023年第2期357-362,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62164005)资助的课题.

摘　　要：利用现代材料生长技术纳米厚的半导体可以沿着良好的方向有序生长,形成层状半导体纳米结构.在这种半导体纳米结构中由于结构反演对称性破缺出现较强的自旋-轨道耦合,能有效消除半导体中电子的自旋简并,导致电子自旋极化效应,在自旋电子学领域中具有重要的应用.本文从理论上研究了单层半导体纳米结构中由Rashba型自旋-轨道耦合引起的电子自旋极化效应.由于Rashba型自旋-轨道耦合,相当强的电子自旋极化效应出现在该单层半导体纳米结构中.自旋极化率与电子的能量和平面内波矢有关,尤其是其可通过外加电场或半导体层厚度进行调控.因此,该单层半导体纳米结构可作为半导体自旋电子器件应用中的可控电子自旋过滤器.Nanothick semiconductors can grow orderly along a desired direction with the help of modern materials growth technology such as molecular beam epitaxy,which allows researchers to fabricate the so-called layered semiconductor nanostructure(LSN)experimentally.Owing to the structure inversion symmetry broken by the layered form in the LSN,the electron spins interact tightly with its momentums,in the literature referred to as the spin-orbit coupling(SOC)effect,which can be modulated well by the interfacial confining electric field or the stain engineering.These significant SOC effects can effectively eliminate the spin degeneracy of the electrons in semiconductor materials,induce the spin splitting phenomenon at the zero magnetic field and generate the electron-spin polarization in the semiconductors.In recent years,the spin-polarized transport for electrons in the LSN has attracted a lot of research interests,which is because of itself scientific importance and potential serving as spin polarized sources in the research field of semiconductor spintronics.Adopting the theoretical analysis combined with the numerical calculation,we investigate the spin-polarized transport induced by the Rashba-type SOC effect for electrons in a single-layered semiconductor nanostructure(SLSN)-InSb.The present research is to explore the new way of generating and manipulating spin current in semiconductor materials without any magnetic field,and focuses on developing new electron-spin filter for semiconductor spintronics device applications.The improved transfer matrix method(ITMM)is exploited to exactly solve Schrödinger equation for an electron in the SLSN-InSb device,which allows us to calculate the spin-dependent transmission coefficient and the spin polarization ratio.Owing to a strong Rashba-type SOC,a considerable electron-spin polarization effect appears in the SLSN-InSb device.Because of the effective potential experienced by the electrons in the SLSN-InSb device,the spin polarization ratio is associated with the electron ener

关 键 词：单层半导体纳米结构 自旋-轨道耦合 自旋极化效应 可控电子自旋过滤器 

分 类 号：O469[理学—凝聚态物理]