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.

非技术性摘要目前，除了电子的电荷之外，在当代电子学中，还存在着一种探索电子自旋（电子的量子力学磁性）的作用的激烈的世界性运动，着眼于增加电子微芯片设备的功能，特别是在计算领域。该奖项支持一个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型半导体纳米级结构，其中电子自旋的作用通过引入磁性离子来增强。通过培训研究生和本科生掌握先进的半导体制造技术以及设计多功能材料，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。材料科学的这些领域的技能在美国工业，国家实验室和学术界的广泛需求。此外，圣母大学的团队与许多科学家（目前与超过35个其他机构）合作，要么提供研究样本，要么进行联合实验。随着在本项目过程中开发新的基于自旋的电子材料，这种传播和分享成果和专门知识的活动（其额外好处是使学生接触机构间和学科间的团队合作）预计将进一步扩大。 技术摘要该基金支持一个项目，该项目侧重于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）半导体在其尺寸接近纳米尺寸时的性质变化;以及（B）探索性研究磷化物基FM半导体（如GaMnP和InMnP）的生长和性质。区域（a）的动机是期望，随着诸如GaMnAs的磁性半导体的物理尺寸接近纳米尺度并且变得与例如铁磁畴壁的宽度或自由载流子耗尽长度，其磁特性将显著改变。当人们考虑FM半导体器件在纳米技术中的应用时，这变得特别重要。使用分子束外延（MBE），然后是光刻技术，圣母大学的团队提出通过磁化测量，磁输运，磁光研究和铁磁共振来探索这种减小尺寸的后果。区域（B）主要致力于开展磷化物基铁磁半导体分子束外延生长的综合研究，并对其基于自旋的性质进行系统研究。尽管诸如GaMnP、InMnP和GaMnAsP的合金的自旋性质被预期是非常有前途的，并且提供了一系列重要的新机会，但是与给予例如以下的努力相比，GaMnAs或InMnAs合金。将拟议的研究扩展到这个新的FM半导体家族，预计将大大提高对铁磁半导体的理解。