NIRT: FRG: Collective and Quasiparticle Properties of Nanocrystals and Nano-Arrays

NIRT：FRG：纳米晶体和纳米阵列的集体和准粒子特性

• 批准号: 0210383
• 负责人: Chih-Kang Shih
• 金额: $ 180万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0210383&HistoricalAwards=false
• 关键词: NIRT; FRG; Collective; Quasiparticle; Properties

A fundamental competition between order and disorder lies at the heart of materials science and technology. Interactions between atoms or electrons spaced sub nanometer apart can lead to collective organization into states with long-range order. Order in electronic states gives rise to physical consequences such as magnetism, ferroelectricity and superconductivity. In bulk materials, the collective electronic properties exhibit a characteristic length scale called the coherence length, which corresponds to the minimum grain size in superconductors, and in ferromagnets the domain wall width. These length scales generally exceed or are comparable to geometrical parameters of nanostructured materials. For these reasons nanostructured materials represent an important new frontier for the study of collective electronic behavior. This interdisciplinary research team will study the physical consequences of nanometer-size dimensions on collective and independent electron properties in individual nanocrystals and in controlled nanocrystal arrays. It is unique in the combination of expertise in materials synthesis, materials characterizations and theory that has been brought together at a single institution. It also forges a close partnership with one leading company in information technology and two foreign institutions. Educationally, this NIRT will help lead the campus-wide initiative at UT Austin for training the next generation of scientists in nanoscience through the integration of research and education and a strong partnership with the newly established Center of Nano- and Molecular Science and Techology. It integrates diversity by actively recruiting graduate students in minority groups. It further reaches out to K-12 education in the Austin area. This interdisciplinary program brings together expertise in advanced synthesis of metal and semiconductor nanostructures, expertise in nanoscale characterizations of structural, electronic, transport, optical and magnetic properties, and expertise in mesoscopic and many-body condensed matter theory, working together in a single institution to explore the physical consequences of nanometer-size dimensions on collective and independent electron properties in individual nanocrystals and in controlled nanocrystal arrays. Of particular interests are ferromagnetic, superconducting, and normal metal nanocrystals, and ferromagnetic, semimagnetic, and normal semiconductor quantum dots. In ferromagnetic and superconducting systems the emphasis to date has been on the collective properties that underlie, for example, the use of ferromagnets for information storage and the potential use of small superconductors as quantum-bits. As these particles become smaller, the physics of the magnetic anisotropy barriers essential for information storage will be altered, and superconductivity will be destroyed, respectively. This regime is a frontier for fundamental physics and for materials physics and chemistry, and will be the focus of this research program. This research team also forges a close partnership with one leading company in information technology and two foreign institutions. It will strengthen educational and training efforts at UT Austin in nanoscience and nanotechnology by designing a new curriculum that removes barriers between current disciplinary specialization in different majors and provides an excellent training ground for the future generation of scientists in nanoscale science and technology.

有序和无序之间的根本竞争存在于材料科学和技术的核心。相距亚纳米的原子或电子之间的相互作用可以导致集体组织成具有长程有序的状态。电子态的有序会引起物理后果，如磁性、铁电性和超导电性。在块体材料中，集体电子性质表现出一个称为相干长度的特征长度尺度，它对应于超导体中的最小晶粒度，而在铁磁体中则表现为磁化壁宽。这些长度尺度通常超过或相当于纳米结构材料的几何参数。由于这些原因，纳米结构材料是研究集体电子行为的一个重要的新前沿。这个跨学科的研究小组将研究纳米尺寸对单个纳米晶体和受控纳米晶体阵列中集体和独立电子性质的物理影响。它的独特之处在于，它将材料合成、材料表征和理论方面的专业知识结合在一起，这些专业知识已经在一个机构中汇集在一起。它还与一家领先的信息技术公司和两家外国机构建立了密切的合作伙伴关系。在教育方面，这项NIRT将帮助领导德克萨斯大学奥斯汀分校的校园计划，通过研究和教育的整合以及与新成立的纳米和分子科学与技术中心的强大合作伙伴关系，培训下一代纳米科学科学家。它通过积极招收少数族裔研究生来整合多样性。它进一步延伸到奥斯汀地区的K-12教育。这一跨学科计划汇集了先进的金属和半导体纳米结构合成方面的专业知识，结构、电子、传输、光学和磁性纳米级表征方面的专业知识，以及介观和多体凝聚态理论方面的专业知识，在一个机构中共同探索纳米尺寸尺寸对单个纳米晶体和受控纳米晶体阵列中集体和独立电子性质的物理影响。特别令人感兴趣的是铁磁、超导和正常的金属纳米晶体，以及铁磁、半磁和正常的半导体量子点。在铁磁和超导系统中，到目前为止，重点一直放在集体性质上，例如，将铁磁体用于信息存储，以及将小超导体用作量子比特的潜在用途。随着这些粒子变得更小，信息存储所必需的磁各向异性势垒的物理性质将发生改变，超导电性将分别被摧毁。这一体系是基础物理、材料物理和化学的前沿，也将是本研究计划的重点。该研究团队还与一家领先的信息技术公司和两家外国机构建立了密切的合作伙伴关系。它将加强德克萨斯大学奥斯汀分校在纳米科学和纳米技术方面的教育和培训努力，通过设计新的课程，消除目前不同专业的学科专业化之间的障碍，并为未来一代纳米科学和技术科学家提供良好的培训基础。