NON-MAGNETIC SEMICONDUCTOR SPINTRONICS: INNOVATIONS IN NANOSCALE, HIGHLY SPIN-ORBIT COUPLED QUANTUM WELL SYSTEMS

非磁性半导体自旋电子学：纳米级、高度自旋轨道耦合量子阱系统的创新

基本信息

批准号：
EP/E055583/1
负责人：
Steven Clowes
金额：
$ 74.83万
依托单位：
University of Surrey
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE055583%2F1
关键词：
NON MAGNETIC SEMICONDUCTOR SPINTRONICS INNOVATIONS

项目摘要

The aim of this proposal is to provide new methods of injecting and detecting spin polarised currents in all non-magnetic semiconductor systems. This area, the control of spins using spin-orbit coupling effects, is the subject of intense theoretical activity around the world, though so far relatively little experimental work has been published. One of the primary reasons for the interest is that the challenges in either producing room-temperature magnetic semiconductors or in injecting from magnetic metals are both by-passed. One important reason for the paucity of experimental activity is the difficultly in controlling spin-orbit coupling in the semiconductor materials of primary importance for (opto-)electronics, where the effects are small. The methods presented here utilise the high spin-orbit coupling in narrow gap semiconductor (NGS) quantum well structures, using the latest theories of spin dependent ballistic transport. These materials have recently been shown by UK workers to be capable of delivering the ultimate in speed and power consumption for transistors, and the technology may now be considered as having reached maturity. This proposal will exploit and strengthen the UK's lead in this area, and turn it to new advantage. Devices for spin filtering, emission and detection are proposed which will provide a crucially important set of tools for the spintronic community.Successful development of novel spin-based electronic devices requires establishing new experimental methods of creating, measuring and manipulating spin-polarised currents. According to the International Semiconductor Roadmap in order to realise an all electrical semiconductor spintronic device one of two challenges must be met. Either successful engineering of the ferromagnetic metal/semiconductor interface has to be achieved to incorporate spin preserving tunnel barriers or the fabrication of room temperature dilute magnetic semiconductors compatible with the standard electronic industry's materials (Si, GaAs and GaN). The current proposal describes an alternative solution that utilises existing materials and technologies in a new way. This project will investigate spin kinetics and related phenomena in nanostructures, and apply the physical understanding gained to the creation of a spin polarisation within the semiconductor without reliance on the presence of an external ferromagnetic source. Simply put, I shall exploit the non-degeneracy of moving electron spin states in materials and structures which lack inversion symmetry. For most purposes and in most materials these spin splittings are negligibly small. However, it is possible to utilise the dichromatic nature of electron spin, for example in the ballistic regime at the interface between two materials of different spin-orbit coupling strength. In this emerging field, dubbed 'spin optics', spin dependent reflection has been demonstrated and a similar refraction (and negative refraction) -like effect has been proposed. The ballistic regime also presents the opportunity to use the spin dependent nature of cyclotron motion. Similarly, the spin splitting may be utilised in resonant tunnel diode structures for spin injection and detection, where a voltage applied along growth direction can preferentially allow transmission of either spin up or down electrons. These mechanisms have great potential for spin filters for semiconductor spintronic applications, which avoid the need for spin injection from ferromagnetic metals or dilute magnetic semiconductors.

该提案的目的是提供在所有非磁性半导体系统中注入和检测自旋极化电流的新方法。利用自旋轨道耦合效应控制自旋的这一领域是世界各地理论活动活跃的主题，尽管迄今为止发表的实验工作相对较少。人们感兴趣的主要原因之一是，生产室温磁性半导体或磁性金属注入的挑战都被绕过了。实验活动缺乏的一个重要原因是难以控制对（光）电子学至关重要的半导体材料中的自旋轨道耦合，其影响很小。这里提出的方法利用窄带隙半导体（NGS）量子阱结构中的高自旋轨道耦合，并使用自旋相关弹道输运的最新理论。英国工人最近证明这些材料能够为晶体管提供终极的速度和功耗，并且该技术现在可以被认为已经成熟。该提案将利用和加强英国在这一领域的领先地位，并将其转化为新的优势。提出了用于自旋过滤、发射和检测的器件，这将为自旋电子学界提供一套至关重要的工具。新型自旋电子器件的成功开发需要建立创建、测量和操纵自旋极化电流的新实验方法。根据国际半导体路线图，为了实现全电半导体自旋电子器件，必须满足两个挑战之一。要么必须成功设计铁磁金属/半导体界面，以纳入自旋保持隧道势垒，要么制造与标准电子工业材料（Si、GaAs 和 GaN）兼容的室温稀磁半导体。当前的提案描述了一种以新方式利用现有材料和技术的替代解决方案。该项目将研究纳米结构中的自旋动力学和相关现象，并将获得的物理理解应用于在半导体内创建自旋极化，而不依赖于外部铁磁源的存在。简而言之，我将利用缺乏反演对称性的材料和结构中移动电子自旋态的非简并性。对于大多数用途和大多数材料来说，这些自旋分裂很小，可以忽略不计。然而，可以利用电子自旋的二色性，例如在不同自旋轨道耦合强度的两种材料之间的界面处的弹道状态中。在这个被称为“自旋光学”的新兴领域，自旋相关反射已经被证明，并且已经提出了类似的折射（和负折射）效应。弹道状态还提供了利用回旋加速器运动的自旋相关性质的机会。类似地，自旋分裂可以用在用于自旋注入和检测的谐振隧道二极管结构中，其中沿着生长方向施加的电压可以优先允许自旋向上或向下电子的传输。这些机制对于半导体自旋电子应用的自旋滤波器具有巨大的潜力，可以避免铁磁金属或稀磁半导体的自旋注入。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Strong dependence of spin dynamics on the orientation of an external magnetic field for InSb and InAs

DOI：
10.1063/1.3337111
发表时间：
2010-03
期刊：
Applied Physics Letters
影响因子：
4
作者：
K. Litvinenko;M. Leontiadou;Juerong Li;S. Clowes;M. Emeny;T. Ashley;C. Pidgeon;L. Cohen;B. Murdin
通讯作者：
K. Litvinenko;M. Leontiadou;Juerong Li;S. Clowes;M. Emeny;T. Ashley;C. Pidgeon;L. Cohen;B. Murdin

Manipulation of Spin Dynamics in Semiconductor Structures by Orientation of Small External Magnetic Field

通过小外部磁场的定向操纵半导体结构中的自旋动力学