PIRE: International consortium for probing novel superconductors with neutrons, muons, photons and STM

该项目由来自美国、日本、加拿大、英国和中国的领先超导研究人员组成国际联盟，研究新型超导体，以阐明超导机制和特性，并开发新型超导材料。在传统的电气系统中，热量是由电子与电线中的原子和杂质碰撞时产生的摩擦产生的，这种特性适用于烤面包机或熨斗等电器，但不适用于大多数其他电气应用。超导性可以被认为是“无摩擦”电，电子在原子之间畅通无阻地滑动，从而大大提高了导体的能量效率。迄今为止，这只能在极低的温度下实现；挑战是在室温或接近室温和高电流下利用这种现象。该项目将填补我们目前对超导性理解的空白，调和现有理论，并推进高性能设备和节省成本的电动机、发电机和输电线路的更好材料的开发。该项目利用中子散射、介子自旋弛豫、x射线散射、拉曼光谱和扫描隧道显微镜等强大的实验探测技术，将领先的材料实验学家和著名理论家联系在一起，对FeAs、CuO、CeCoIn5和URu2Si2超导体进行研究。这些先进的方法允许阐明这些重要的新材料的相图，其中一些重要的方面目前是未知的。PIRE团队将探索影响某种材料超导的最高温度的参数，以及提高该温度的方法，以便超导性不需要如此昂贵的制冷。在超流体密度和比热不连续的一些异常，不符合超导的标准理论，也将从实验和理论上进行研究。国际合作对这项工作至关重要，因为它将使美国科学家和学生能够使用英国和加拿大提供的、但美国没有的世界级加速器设施，获得中国和日本制造的高质量标本，并获得来自所有国家的一流科学专业知识。将多个探针在同一高质量标本上的结果进行组合比较，可以显著提高数据的准确性。理论家和实验家在关键概念上的面对面合作将有助于将数学理论转化为现实和有效的模型和材料。该项目非常重视培养学生和早期职业科学家。学生和博士后将在国外进行为期3-6个月的超导机制研究访问，并在那里接受语言和文化培训。该项目将通过为纽约弱势学校的高中生和教师举办讲习班，以及通过超导和扫描隧道显微镜的推广项目，积极招募少数族裔学生进入科学领域。高中生和本科生将通过该项目获得宝贵的光束时间经验，而作为一个在物理科学领域代表性不足的群体，女学生将从团队中的四位女首席科学家那里获得宝贵的指导。PIRE团队还将开发一套基于互联网的现代固态物理讲座和一本介绍固态物理的教科书，以反映凝聚态物理和相关实验技术的最新知识。该项目将加强美国机构的材料研究项目并使其国际化，并吸引更多的美国学生参与国际研究合作。它将把哥伦比亚大学及其学生和教师置于研究和教育伙伴关系的核心，广泛的研究合作，教学合作，以及参与教师和学生频繁的互惠研究访问。影响超出了PI和他的机构，包括为美国学生提供在两个能源部美国国家实验室（橡树岭和洛斯阿拉莫斯）进行研究的机会，以及在英国的ISIS和加拿大的TRIUMF设施培训早期职业科学家，这两个设施都将为美国和日本正在建设的新探测设施建立核心劳动力。该项目将建立在现有的美洲材料科学网络（CIAM）的基础上，并为五个参与国的科学家和机构之间的长期研究和教育合作奠定基础，所有这些都将推动超导及其应用的最新发展。参与的美国机构包括哥伦比亚大学（NY）、田纳西大学诺克斯维尔分校以及能源部的橡树岭（TN）和洛斯阿拉莫斯（NM）国家实验室。国外机构包括中国科学院物理研究所、英国布里斯托大学、英国科学技术设施委员会ISIS设施、加拿大麦克马斯特大学、加拿大粒子与核物理国家实验室、日本东京大学、日本大阪大学、日本东北大学和日本国家先进工业科学技术研究院。该奖项由国际科学与工程办公室和材料研究部共同资助。

This PIRE project forms an international consortium of leading superconductivity researchers from the U.S., Japan, Canada, UK, and China to investigate novel superconductors to clarify superconducting mechanisms and properties and develop novel superconducting materials. In conventional electrical systems heat is generated by friction as electrons collide with atoms and impurities in the wire, a property that is ideal for appliances such as toasters or irons but not for most other electrical applications. Superconductivity can be thought of as "frictionless" electricity whereby electrons glide unimpeded between atoms, thus vastly improving the conductor's energy efficiency. To date this has only been achieved at extremely low temperatures; the challenge is to harness this phenomenon at or near room temperature and at high electrical currents. This project will fill gaps in our current understanding of superconductivity, reconcile current theories, and advance the development of better materials for fast-performing devices and cost-saving electric motors, generators, and power transmission lines. The project links leading materials experimentalists and eminent theorists in a study of FeAs, CuO, CeCoIn5, and URu2Si2 superconductors using powerful experimental probing techniques including neutron scattering, muon spin relaxation, X-ray scattering, Raman spectroscopy, and scanning tunneling microscopy. These advanced methods allow elucidation of the phase diagrams of these important new materials of which some significant aspects are currently unknown. The PIRE team will explore the parameters affecting the highest temperature at which a certain material is superconducting and ways of increasing that temperature so that superconductivity will not require such expensive refrigeration. Some anomalies in the superfluid density and specific heat discontinuities, inconsistent with the standard theory of superconductivity, will also be investigated both experimentally and theoretically. International collaboration is essential for this work because it will provide U.S. scientists and students with access to critical world-class accelerator-based facilities available in the UK and Canada but not in the U.S., to high quality specimens fabricated in China and Japan, and to first-rate scientific expertise from all countries. Combining and comparing the results of multiple probes on the same high-quality specimens will significantly improve the accuracy of data. Face to face collaboration of theorists and experimentalists focused on key concepts will facilitate the translation of mathematical theory into realistic and effective models and materials. The project places great emphasis on training students and early career scientists. Students and postdoctoral researchers will undertake 3-6 month research visits to work on superconducting mechanisms at foreign sites, where they will also receive language and cultural training. The project will actively recruit minority students into the sciences via workshops for high-school students and teachers from disadvantaged schools in New York and via an outreach program on superconductivity and scanning tunneling microscopy. High school and undergraduate students will gain valuable beam-time experience through the project, and female students, who are as a group underrepresented in the physical sciences, will be provided valuable mentoring from four female leading scientists on the team. The PIRE team will also develop a contemporary, internet-based set of solid state physics lectures and a text book on introductory solid state physics that reflect current knowledge in condensed matter physics and related experimental techniques. The project will strengthen and internationalize materials research programs at the U.S. institutions and engage more U.S. students in international research collaborations. It will place Columbia University and its students and faculty at the core of a research and education partnership with extensive research collaborations, teaching cooperation, and frequent reciprocal research visits for participating faculty and students. Impacts extend beyond the PI and his institution, including providing U.S. students with research opportunities at two Department of Energy U.S. National Laboratories (Oak Ridge and Los Alamos) and training of early career scientists at the UK's ISIS and Canada's TRIUMF facilities, both of which will build the core workforce for new probing facilities currently under construction in the U.S. and Japan. This PIRE project will build upon an existing Inter American materials science network (CIAM) and forge a foundation for long-term research and educational collaborations among scientists and institutions in the five participating nations, all advancing the state-of-the-art in superconductivity and its applications. Participating U.S. institutions include Columbia University (NY), University of Tennessee at Knoxville, and the Department of Energy's Oak Ridge (TN) and Los Alamos (NM) National Laboratories. Foreign institutions include Institute of Physics - Chinese Academy of Sciences, University of Bristol (UK), the UK Science and Technology Facilities Council's ISIS facility, McMaster University (Canada), TRIUMF Canada's National Laboratory for Particle and Nuclear Physics, Tokyo University (Japan), Osaka University (Japan), Tohoku University (Japan), and the National Institute of Advanced Industrial Science and Technology (AIST) (Japan).This award is co-funded by the Office of International Science and Engineering and the Division of Materials Research.