RS Fellow - EPSRC grant (2014): Mitigating spin-current relaxation in spin-orbit coupled graphene: towards spin current routing in 2D carbon

RS 研究员 - EPSRC 资助 (2014)：减轻自旋轨道耦合石墨烯中的自旋电流弛豫：实现二维碳中的自旋电流路由

基本信息

批准号：
EP/N004817/1
负责人：
Aires Ferreira
金额：
$ 33.22万
依托单位：
University of York
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FN004817%2F1
关键词：
RS Fellow EPSRC grant 2014

项目摘要

Graphene has opened a new chapter in solid-state physics due its fascinating electronic properties and high potential for innovative applications in domains as diverse as flexible electronics and solar cells. One aspect of graphene research that is currently attracting much attention is in the control of a fundamental property of electrons known as spin. This dictates that an electron is always in one of two possible states, either 'up' or 'down', meaning that the electron itself could provide the basis for a binary logic bit ('0' or '1'). Devices based on such a concept promise faster processing speeds with less energy consumption than current charge-based technologies. However, the practical realisation of spin-based transistors awaits emergent nanomaterials enabling efficient manipulation of the spin state of charge currents. Graphene is one of the most promising candidates due to the fact that it entirely consists of a 2D network of carbon that is only one atom thick. This feature leads to extreme surface sensitivity and the possibility to very precisely tailor electronic, chemical, and magnetic properties through, for example, adsorption of atomic species (adatoms). We have recently predicted that adatoms leading to local enhancement of the spin-orbit coupling in graphene can drive the formation of macroscopic spin currents in the absence of magnetic fields, a phenomenon known as the spin Hall effect. An outstanding question is concerned with the main spin relaxation mechanisms that limit the lifetimes of spin signals generated through the spin Hall effect in adatom-decorated graphene. This theoretical project will employ a broad scope approach, combining analytical tools and a novel method for fully quantum transport simulations with billions of atoms, to uncover adatom decorations incorporating both robust spin current generation and spin coherence over relevant time scales. The latter is a crucial step towards the implementation of spin logic functions necessary to explore the recently discovered spin Hall effect.

由于其引人入胜的电子特性以及在柔性电子和太阳能电池等多样化的域中，石墨烯在固态物理学上开了一个新的章节。石墨烯研究目前引起了很多关注的一个方面是控制电子旋转的基本特性。这决定电子始终处于“向上”或“向下”的两个可能状态之一，这意味着电子本身可以为二进制逻辑位（“ 0''或'1'）提供基础。基于这样的概念的设备承诺，与当前基于电荷的技术相比，能源消耗更快的处理速度更快。但是，基于自旋的晶体管的实际实现等待着出现的纳米材料，从而有效地操纵了旋转电荷电流。石墨烯是最有前途的候选人之一，因为它完全由一个仅是一个原子厚的碳网络组成。此特征导致表面敏感性极端，并通过例如原子种类的吸附（Adatoms）来精确地量身定制电子，化学和磁性。我们最近预测，在没有磁场的情况下，导致石墨烯中自旋轨道耦合局部增强的ADATOM可以驱动宏观自旋电流的形成，这一现象称为自旋大厅效应。一个杰出的问题与主要的自旋松弛机制有关，这些机制限制了通过旋转厅效应在Adatom装饰的石墨烯中生成的自旋信号的寿命。这个理论项目将采用广泛的范围方法，结合分析工具和一种新颖的方法，用于完全量子传输模拟与数十亿个原子，以揭示ADATOM装饰，并在相关时间尺度上结合了强大的自旋电流和旋转连贯性。后者是朝着探索最近发现的旋转厅效应所需的旋转逻辑功能实施的关键步骤。