CAREER: Spin-Spin Interactions, Magnetic Order and Low-Dimensional Effects in Magnetic Semiconductors: Education and Research at the Nanoscale with Spin-Polarized STM

在过去的几年里，新一代基于自旋的器件（自旋电子学）的可能性推动了磁系统的基础研究。基于自旋的设备具有比传统的基于电荷的电子设备更快和消耗更少功率的潜力。稀磁半导体（DMS）目前被认为是实现自旋电子器件的最有前途的途径之一，但在室温下缺乏具有磁性载流子的半导体仍然是这一奋进的重要瓶颈。这个教师早期职业项目的目标是使用扫描隧道显微镜（STM）和一种相对较新的技术，自旋极化STM（SP-STM）探索稀磁半导体的基本特性。SP-STM在揭示原子尺度下的磁性方面具有巨大的潜力。了解稀磁半导体中自旋和电荷行为的细节可能会为自旋电子技术的可行性指明方向。这个综合项目将利用纳米科学和纳米技术领域的兴奋，吸引初中和高中学生的科学。在该项目中拟议的推广活动是面向寻找有效的方法，减少相当大的性别差距在物理学和engineering.Technical AbstractionUnexpected阶段和有趣的现象是系统的特点，涉及相互作用的量子自旋。磁性半导体也是如此，最近关于自旋库仑阻力、自旋力矩效应的报道，以及在自旋电子器件中应用的强大潜力，引领着一个令人兴奋的新领域。这个教师早期职业项目的目标是探索稀磁半导体在纳米级使用低温扫描隧道光谱和一个相对较新的技术，自旋极化STM（SP-STM）的基本属性。对这些自旋电子材料的SP-STM研究将揭示重要的基础物理以及与材料相关的问题，如：（a）自旋-自旋相互作用和磁畴的有效长度尺度，（B）短程相互作用如何导致长程有序，（c）团簇/沉淀物对磁有序的影响以及（d）电子和磁性如何随维度变化。本提案的教育和推广部分与项目的研究目标密切相关。在所有的推广计划中，一个反复出现的主题将是通过接触纳米科学的最新进展和未来应用的潜力，为物理和技术带来兴奋。

Non-technical abstractIn the last few years, the possibility of a new generation of spin based devices (spintronics), has given impetus to fundamental studies of magnetic systems. Spin based devices have the potential to be faster and consume less power than traditional charge based electronics. Dilute magnetic semiconductors (DMS) are currently being pursued as one of the most promising avenues of realizing spintronic devices, but the lack of semiconductors with magnetic carriers at room temperature remains a significant bottleneck in this endeavor. The goal of this Faculty Early Career project is to explore the fundamental properties of dilute magnetic semiconductors using scanning tunneling microscopy (STM) and a relatively new technique, spin-polarized STM (SP-STM). SP-STM has tremendous potential to shed light on magnetic properties at atomic length scales. Understanding the details of the behaviour of spin and charge in dilute magnetic semiconductors might point the way towards making spintronic technology viable. This integrated project will capitalize on the excitement in the field of nanoscience and nanotechnology to attract middle and high school students to the sciences. The proposed outreach activities in the project are geared towards finding effective methods of decreasing the substantially large gender-gap in physics and engineering.Technical AbstractUnexpected phases and interesting phenomena are the hallmarks of systems involving interacting quantum spins. So it is with magnetic semiconductors, with recent reports of spin Coulomb drag, spin-torque effect, and a strong potential for applications in spintronic devices, leading the way to what promises to be an exciting new field. The goal of this Faculty Early Career project is to explore the fundamental properties of dilute magnetic semiconductors at the nanoscale using low temperature scanning tunneling spectroscopy and a relatively new technique, spin-polarized STM (SP-STM). SP-STM studies on these spintronic materials will shed light on important basic physics as well as materials related issues such as: (a) effective length scales of spin-spin interactions and magnetic domains, (b) how short range interactions lead to long range order, c) effect of clusters/precipitates on magnetic order and (d) how electronic and magnetic properties change with dimensionality. The education and outreach components of this proposal are strongly intertwined with the research goals of the project. A recurring theme in all outreach programs will be to generate excitement for physics and technology by exposure to recent advances in nanoscale science and potential for future applications.