半导体二维电子体系自旋退相干与自旋输运实验研究：自旋－轨道耦合效应

项目名称： 半导体二维电子体系自旋退相干与自旋输运实验研究：自旋－轨道耦合效应

项目编号： No.11274302

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张新惠

作者单位： 中国科学院半导体研究所

项目金额： 93万元

中文摘要： 本项目选取具有器件应用潜能的III-V族半导体二维电子气体系，利用时间分辨超快磁光光谱技术，系统研究半导体二维电子体系中自旋弛豫、退相干以及自旋输运过程受自旋－轨道耦合效应调控的物理规律，并特别研究高指数面[111]晶向GaAs衬底上生长的GaAs量子阱二维电子与自旋的退相干与输运过程研究及其自旋－轨道耦合调控。本项目将设计一系列分子束外延生长在[100]、[110]、[111]不同晶向GaAs衬底上的GaAs量子阱结构，对受限电子能级进行系统设计与剪裁（如阱宽、势垒高度、调制掺杂等的系统变化），结合外加电场、磁场、栅压等不同手段，通过自旋退相干与自旋输运动力学过程的实验研究，实验测量Dresselhaus和Rashba自旋－轨道耦合相对与绝对强度随电子能带剪裁、空间结构对称性、外场、温度、载流子相互作用的变化，揭示并实现利用自旋－轨道耦合效应调控自旋相干演化与输运动力学的物理规律与实验方

中文关键词： 半导体二维电子体系；自旋退相干；自旋输运；自旋-轨道耦合效应；超快磁光光谱

英文摘要： This proposal will focus on the ultrafast magneto-optical studies of electron spin relaxation and dephasing as well as spin transport dynamics via manipulation of spin-orbit coupling in typical III-V group two dimensional electron gas system, which has potential device application. In particular, the electron spin dephasing and transport dynamics via manipulation of spin-orbit coupling in high index-grown [111] GaAs quantum wells will be experimentally investigated. A series of GaAs quantum well structures grown with molecular beam epitaxy along [100], [110] and [111] will be theoretically designed with systematical electron energy engineering (such as different crystal direction; different well/barrier width; barrier height; modulation doping, etc), combining additional control with external electric /magnetic field and gating so on. Through the experimental studies of electron spin relaxation and dephasing as well as spin transport dynamics, the relative and absolute strength of Dresselhaus and Rashba spin-orbit coupling will be experimentally determined as function of electron energy band, structural symmetry, external fields, temperature and electron interactions so on. The ultimate goal of this proposal is to experimentally fulfill the practical methods, and at the meantime, reveal the fundamental physics f

英文关键词： two-domensional semiconductor system；spin dephasing；spin transport；spin-orbit coupling；ultrafast magneto-optical spectroscopy