Itinerant Spin-Dynamics in Structures of Reduced Dimensionality

降维结构中的巡回自旋动力学

基本信息

批准号：
163472456
负责人：
Professor Dr. Stefan Kettemann
金额：
--
依托单位：
Department of Physics and Earth Sciences
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/163472456?language=en
关键词：
Itinerant Spin Dynamics Structures Reduced

项目摘要

In this project we intend to study the spin dynamics and quantum transport in disordered semiconductor quantum wires with spin-orbit coupling using the methods we have developed recently within the project B9 of SFB 508. In particular, we will derive the dependence of the spin relaxation rate and the weak localisation correction to the conductance on the strength and the kind of spin-orbit interaction (linear and cubic Dresselhaus, as well as Rashba coupling), growth direction, width of the quantum wires, mobility and temperature. Furthermore, the result is expected to depend on the smoothness of the transversal confinement of the quantum wires. We are motivated by recent experiments [A1-A7] which report the dimensional reduction of the spin relaxation rate in agreement with our previous results, but are raising new questions, in particular as regards the crossover from diffusive to ballistic wires, and dependence on growth direction and confinement potential. These results call for a nontrivial extension of our previous derivations, which were derived in the diffusive regime.Furthermore, experimental results which were recently interpreted as antilocalisation in magnetic semiconductor quantum wires [A8], require a further extension of the theory in order to be able to calculate the magnetconductivity in these magnetic materials.Motivated by experiments which report a minimal spin relaxation rate at the metal-insulator transition in n-doped GaAs [A9], we will also study the Dyakonov-Perel-spin relaxation in a multifractal state at the Anderson-metal-insulator transition, using an analytical method developed recently

在这个项目中，我们打算使用我们最近在 SFB 508 项目 B9 中开发的方法，研究具有自旋轨道耦合的无序半导体量子线中的自旋动力学和量子输运。特别是，我们将推导出自旋弛豫的依赖性速率和对自旋轨道相互作用的强度和类型（线性和立方 Dresselhaus，以及 Rashba 耦合）、生长方向、量子线宽度、迁移率和温度的电导的弱局域化校正。此外，预计结果将取决于量子线横向限制的平滑度。我们受到最近实验 [A1-A7] 的启发，该实验报告了自旋弛豫率的尺寸减小，与我们之前的结果一致，但提出了新的问题，特别是关于从扩散线到弹道线的交叉以及对生长的依赖性方向和限制潜力。这些结果需要对我们之前的推导进行非平凡的扩展，这些推导是在扩散区域中导出的。此外，最近被解释为磁性半导体量子线中反局域化的实验结果[A8]，需要进一步扩展该理论才能被能够计算这些磁性材料的磁导率。受到 n 掺杂 GaAs [A9] 金属-绝缘体转变时最小自旋弛豫率的实验的启发，我们还将研究使用最近开发的分析方法，在安德森-金属-绝缘体转变时处于多重分形状态的 Dyakonov-Perel-自旋弛豫