MRI: Equipment Development: Development of Advanced Scanning Probe Techniques for Spintronics and Nanodevice Research

MRI：设备开发：用于自旋电子学和纳米器件研究的先进扫描探针技术的开发

• 批准号: 0320654
• 负责人: Venkatesh Narayanamurti
• 金额: $ 38.4万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0320654&HistoricalAwards=false
• 关键词: MRI; Equipment; Development; Advanced; Scanning

Intellectual MeritScanning Probe Microscopy (STM, AFM, BEEM etc) has revolutionized the way we visualize and manipulate individual atoms, chemical bonds, and electron waves. A successful development of a new technique and instrument that can enable us to visualize and manipulate magnetic states and even a single spin would clearly be another great milestone in device and materials research. An STM is just a two terminal device but the investigation of spin-dependent nanoscale transport phenomenon, similar to transistor action, requires a three terminal device arrangement. Here we propose to construct a dual-probe scanning tunneling microscope operating in a low temperature, high magnetic field and ultra high vacuum environment. Such an instrument not only maintains independent scanning capability but also is capable of positioning the two tips (electrodes) at nanoscale distances and desired locations, forming a nano-scale three-terminal device with the specimen. Using spin polarized STM tips, this instrument will enable us to inject, detect and manipulate both charges and spins with the controllability down to the atomic scale. It should enable many new experiments including but not limited to: (a) mapping local spin polarization in a dilute magnetic semiconductor based on the Zeeman splitting of the energy spectra of an electron in a high magnetic field; (b) investigating spin injection from a ferromagnetic metal into a semiconductor using a dual tip BEEM; (c) demonstrations of spin FET devices;These studies should enable deeper fundamental understanding of ferromagnetism in semiconductors and other device materials, provide guidance for improving materials performance such as higher Curie temperature and long mean free path for spin coherent carriers, and enable development of novel device concepts based on spin degrees of freedom, in addition to charge degrees of freedom. The unique and powerful capabilities of the proposed instrument cannot be achieved by any current conventional SPM instrument or lithographical fabrication technique.Broader ImpactIt will attract and enable the undergraduate, graduate students, and postdoctoral fellows to explore the most forefront nanoscale device and materials physics, particularly spintronics. This proposed research involves a broad set of experimental skills and should provide a rather special opportunity for training the next generation of experimental physicists and engineers.

扫描探针显微镜（STM，AFM，BEEM等）已经彻底改变了我们可视化和操纵单个原子，化学键和电子波的方式。一种新技术和仪器的成功开发，使我们能够可视化和操纵磁状态，甚至是单个自旋，显然将是器件和材料研究的另一个伟大里程碑。STM只是一个两端器件，但研究自旋相关的纳米级传输现象，类似于晶体管的作用，需要一个三端器件的安排。在这里，我们建议建立一个双探针扫描隧道显微镜工作在低温，高磁场和超高真空环境。这样的仪器不仅保持独立的扫描能力，而且能够将两个尖端（电极）定位在纳米级的距离和所需的位置，形成一个纳米级的三端装置与标本。利用自旋极化STM针尖，这台仪器将使我们能够注入，检测和操纵电荷和自旋的可控性下降到原子尺度。它将使许多新的实验成为可能，包括但不限于：（a）基于强磁场中电子能谱的塞曼分裂来绘制稀磁半导体中的局部自旋极化;（B）使用双尖端BEEM来研究从铁磁金属到半导体中的自旋注入;（c）自旋FET器件的演示;这些研究将使人们对半导体和其他器件材料中的铁磁性有更深的基本认识，为提高材料性能提供指导，例如提高居里温度和自旋相干载流子的长平均自由程，并且能够开发基于自旋自由度以及电荷自由度的新颖器件概念。该仪器独特而强大的性能是目前任何传统的SPM仪器或光刻制造技术所无法实现的，它将吸引并使本科生、研究生和博士后研究员能够探索最前沿的纳米器件和材料物理，特别是自旋电子学。这项拟议的研究涉及广泛的实验技能，应该为培训下一代实验物理学家和工程师提供一个相当特殊的机会。