Electron Spin Effects in Semiconductor Nanostructures

半导体纳米结构中的电子自旋效应

• 批准号: 1400432
• 负责人: Margaret Dobrowolska
• 金额: $ 47.33万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1400432&HistoricalAwards=false
• 关键词: Electron; Spin; Effects; Semiconductor; Nanostructures

NON-TECHNICAL ABSTRACTThere is currently an intense worldwide movement to explore the role of the electron spin (a quantum-mechanical magnetic property of the electron) in addition to the electron's charge in contemporary electronics, with an eye on increasing the functionality of electronic microchip devices, particularly in the realm of computation. This award supports a project aimed at addressing this issue by employing state-of-the-art techniques to fabricate and characterize a series of novel semiconductor nanometer scale structures in which the role of the electron spin is enhanced by incorporating magnetic ions. By training graduate and undergraduate students in cutting-edge semiconductor fabrication techniques as well as in designing multi-functional materials, the project is expected to have broad impact far beyond its immediate purely scientific goals. Skills in these areas of materials science are in wide demand in U.S. Industry, National Laboratories, and Academia. Additionally, the Notre Dame team collaborates with many scientists (currently with more than thirty-five other institutions) either by providing research samples or by carrying out joint experiments. This activity of dissemination and sharing of results and know-how (which has the added benefit of exposing students to inter-institutional and inter-disciplinary team collaborations) is expected to further expand as new spin-based electronic materials are developed in the course of the present project. TECHNICAL ABSTRACTThis grant supports a project that focuses on two new but complementary areas involving spin phenomena in low-dimensional magnetic semiconductor systems. (a) The study of changes in the properties of ferromagnetic (FM) semiconductors as their size approaches nanometer dimensions; and (b) exploratory research on growth and properties of phosphide-based FM semiconductors, such as GaMnP and InMnP. Area (a) is motivated by the expectation that, as the physical size of a magnetic semiconductor such as GaMnAs approaches the nanometer scale and becomes comparable to, e.g., the width of ferromagnetic domain walls or the free carrier depletion length, its magnetic properties will significantly change. This becomes especially important as one considers applications of FM semiconductor devices in nanotechnology. Using molecular beam epitaxy (MBE) followed by lithographic techniques, the Notre Dame team proposes to explore the consequences of such reduced size by magnetization measurements, magneto-transport, magneto-optical studies, and ferromagnetic resonance. Area (b) is focused on developing comprehensive research on MBE growth of phosphide-based ferromagnetic semiconductors, followed by a systematic investigation of their spin-based properties. Although the spin properties of alloys such as GaMnP, InMnP and GaMnAsP are expected to be highly promising, and offer a range of important new opportunities, surprisingly little work has been done on this family of materials as compared to the effort given to, e.g., the GaMnAs or InMnAs alloys. Extending the proposed studies to this new family of FM semiconductors is expected to significantly advance the understanding of ferromagnetic semiconductors generally.

非技术摘要目前，全球范围内掀起了一场激烈的运动，探索电子自旋（电子的量子力学磁性）以及电子电荷在当代电子学中的作用，着眼于提高电子微芯片设备的功能，特别是在计算领域。该奖项支持旨在解决这一问题的项目，该项目采用最先进的技术来制造和表征一系列新颖的半导体纳米级结构，其中通过结合磁性离子来增强电子自旋的作用。通过对研究生和本科生进行尖端半导体制造技术以及多功能材料设计方面的培训，该项目预计将产生广泛的影响，远远超出其直接的纯科学目标。美国工业界、国家实验室和学术界对材料科学这些领域的技能有着广泛的需求。此外，圣母大学团队还与许多科学家（目前与超过三十五家其他机构）合作，提供研究样本或进行联合实验。随着本项目过程中新的基于自旋的电子材料的开发，这种传播和分享成果和专业知识的活动（其额外好处是让学生接触到机构间和跨学科团队合作）预计将进一步扩大。 技术摘要这笔赠款支持一个项目，该项目重点关注两个新的但互补的领域，涉及低维磁性半导体系统中的自旋现象。 (a) 研究铁磁（FM）半导体尺寸接近纳米尺寸时其特性的变化； (b) 对磷化物基 FM 半导体（例如 GaMnP 和 InMnP）的生长和性能进行探索性研究。区域（a）的动机是这样的预期：当磁性半导体（例如 GaMnAs）的物理尺寸接近纳米尺度并变得与铁磁畴壁的宽度或自由载流子耗尽长度相当时，其磁性将显着变化。当人们考虑 FM 半导体器件在纳米技术中的应用时，这一点变得尤为重要。圣母大学团队利用分子束外延 (MBE) 和光刻技术，建议通过磁化测量、磁输运、磁光研究和铁磁共振来探索尺寸减小的后果。 (b) 领域的重点是对磷化物基铁磁半导体的 MBE 生长进行全面研究，然后对其基于自旋的特性进行系统研究。尽管 GaMnP、InMnP 和 GaMnAsP 等合金的自旋性能预计将非常有前途，并提供一系列重要的新机遇，但令人惊讶的是，与 GaMnAs 或 InMnAs 合金等合金相比，在该材料系列上所做的工作却很少。将拟议的研究扩展到这一新的 FM 半导体系列预计将显着增进对铁磁半导体的总体理解。