Superconductivity and Magnetism of Strongly Correlated Electron Systems Studied by MuSR

MuSR研究强关联电子系统的超导性和磁性

• 批准号: 0102752
• 负责人: Yasutomo Uemura
• 金额: $ 36万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0102752&HistoricalAwards=false
• 关键词: Superconductivity; Magnetism; Strongly; Correlated; Electron

This individual investigator award funds research that aims to apply the muon spin relaxation (MuSR) technique to the study of superconductivity and magnetism in a variety of systems including; high-Tc cuprate, intercalated HfNCl, other superconductors, and low-dimensional and/or geometrically frustrated spin systems. The MuSR method will allow accurate determination of the magnetic field penetration depth in type-II superconductors, and of spontaneous magnetic fields and spin fluctuations in magnetic materials. This project will also include attempts of charge doping via the formation of field effect transistors (FET). The MuSR and FET results will elucidate the evolution from insulators to superconductors to simple metals in superconductors, and from spin singlet states to frozen spin states in magnetic systems. Emerging pictures will be considered from a unified point of view regarding crossover from gapped to ungapped states near quantum phase transitions. The project will also support highly motivated graduate students at Columbia, give them the unique experience of international collaboration, and promote a greater role of female PhD students / researchers in experimental physics. %%%During the recent 15 years, several novel superconductors with very high transition temperatures have been discovered. They include high-Tc copper oxides and intercalated HfNCl. Muon spin relaxation (MuSR) is a new and powerful experimental method for studying superconducting and magnetic properties of solids by using a beam of sub-atomic particles (Mu-meson) produced by high-intensity proton accelerators. This individual investigator award will support research in which the Columbia University group will apply the MuSR technique to studies of several high-Tc superconductors and relevant magnetic materials to elucidate how charges and spins are correlated to exhibit a variety of novel phenomena in solids. This project will provide information crucial for increasing transition temperatures, which would help in the application of high-Tc superconductors to commercial electronic devices and power cables. The project will also support highly motivated graduate students at Columbia, give them the unique experience of international collaboration, and promote a greater role of female PhD students / researchers in experimental physics.***

该个人研究者奖资助旨在将μ子自旋弛豫（MuSR）技术应用于各种系统中的超导性和磁性研究的研究，包括；高tc铜，插层HfNCl，其他超导体，低维和/或几何受挫自旋系统。MuSR方法可以精确测定ii型超导体中的磁场穿透深度，以及磁性材料中的自发磁场和自旋波动。该项目还将包括通过形成场效应晶体管（FET）进行电荷掺杂的尝试。MuSR和FET的结果将阐明从绝缘体到超导体，再到超导体中的简单金属，以及从磁系统中的自旋单重态到冷冻自旋态的演变。新兴的图像将从一个统一的观点来考虑在量子相变附近从间隙态到未间隙态的交叉。该项目还将支持哥伦比亚大学积极进取的研究生，为她们提供独特的国际合作经验，并促进女性博士生/研究人员在实验物理领域发挥更大的作用。在最近的15年中，已经发现了几种具有很高转变温度的新型超导体。它们包括高tc铜氧化物和插层HfNCl。μ子自旋弛豫（MuSR）是利用高强度质子加速器产生的亚原子粒子束（μ介子）研究固体超导和磁性能的一种新的有力实验方法。这项个人研究者奖将支持哥伦比亚大学的研究小组将MuSR技术应用于几种高tc超导体和相关磁性材料的研究，以阐明电荷和自旋是如何相互关联的，从而在固体中表现出各种新现象。该项目将为提高转变温度提供关键信息，这将有助于将高tc超导体应用于商业电子设备和电力电缆。该项目还将支持哥伦比亚大学的高积极性研究生，为他们提供独特的国际合作经验，并促进女性博士研究生/研究人员在实验物理领域发挥更大的作用