RUI: Probing Spin and Charge States in Electron-Correlated Materials by Nuclear Resonance

RUI：通过核共振探测电子相关材料中的自旋和电荷态

• 批准号: 9820631
• 负责人: Oscar Bernal
• 金额: $ 22.95万
• 依托单位: California State L A University Auxiliary Services Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9820631&HistoricalAwards=false
• 关键词: RUI; Probing; Spin; Charge; States

Bernal9820631This is an experimental condensed matter physics project that concentrates on the study of intrinsic inhomogeneous structures in electron-correlated materials. The project will characterize both static and dynamic properties of local magnetic-field and electric-field-gradient distributions by means of magnetic- and quadrupolar-resonance techniques. Electron-correlated materials (systems in which the electrons interact strongly with each other resulting in a macroscopic behavior completely different from that displayed by more common non-interacting electron systems, such as normal metals) display richness in behavior as a response to changes in temperature and magnetic field. Examples of such behavior are superconductivity, magnetism, antiferromagnetism, small-moment and quadrupolar ordering, non-Fermi-liquid behavior, and colossal magnetoresistance. The emphasis of the project is on elucidating the role-played by temperature-dependent magnetic inhomogenieties on the intrinsic behavior of non-Fermi-liquid materials and heavy-fermion antiferromagnets, and in characterizing spin and charge structures (stripes) in the lanthanum nickelates. To this end, the project will study stoichiometric heavy-fermion compounds and related alloys, and 61Ni-enriched La2-xSrxNiO4+d. Through the project, training will be achieved of undergraduate and graduate (masters level) students in the techniques of magnetic resonance, radio-frequency electronics, cryogenics, and computer interface. The project will be carried out in collaboration with The University of California, Riverside, The University of Florida, and the Kamerlingh Onnes Lab in the Netherlands.%%%This is an experimental condensed matter physics project that concentrates on the understanding of electron-correlated materials. These are systems in which the electrons interact strongly with each other, resulting in a behavior completely different from that displayed by the more common non-interacting electron systems such as normal metals. Electron-correlated materials are currently the subject of great deal of interest for science and technology. From the scientific point of view, they are interesting because of the richness in behavior they display in response to changes in temperature and magnetic field. Technologically, the properties that have been discovered in these systems, such as superconductivity, and colossal magnetoresistance, make them potential candidates for future applications. The project is a contribution to a wider effort of condensed matter research by the scientific community at the national and international levels. It will deal with the application of nuclear resonance techniques to study the properties of electron distributions in compounds containing uranium and cerium such as the so-called heavy-fermion systems as well as in the lanthanum nickelates. The emphasis is on elucidating the role played by intrinsic inhomogeneous structures that may be forming in these materials as the temperature is decreased. Through the project, training will be achieved of undergraduate and graduate (masters level) students in the techniques of magnetic resonance, radio-frequency electronics, cryogenics, and computer interface. The project will be carried out in collaboration with The University of California, Riverside, The University of Florida, and the Kamerlingh Onnes Lab in the Netherlands.***

Bernal9820631这是一个实验凝聚态物理项目，专注于电子相关材料中固有非均匀结构的研究。该项目将通过磁共振和四极共振技术来表征局部磁场和电场梯度分布的静态和动态特性。电子相关材料（其中电子彼此强烈相互作用的系统，导致其宏观行为与更常见的非相互作用电子系统（例如普通金属）所表现出的宏观行为完全不同）显示出丰富的行为作为对温度和磁场变化的响应。这种行为的例子有超导性、磁性、反铁磁性、小矩和四极有序、非费米液体行为和巨磁阻。该项目的重点是阐明温度依赖性磁不均匀性对非费米液体材料和重费米子反铁磁体的本征行为所起的作用，以及表征镍酸镧中的自旋和电荷结构（条纹）。为此，该项目将研究化学计量重费米子化合物及相关合金，以及富集61Ni的La2-xSrxNiO4+d。通过该项目，将对本科生和研究生（硕士）学生进行磁共振、射频电子学、低温学和计算机接口技术方面的培训。该项目将与加州大学河滨分校、佛罗里达大学和荷兰 Kamerlingh Onnes 实验室合作开展。%%%这是一个实验性凝聚态物理项目，专注于对电子相关材料的理解。在这些系统中，电子彼此强烈相互作用，导致其行为与更常见的非相互作用电子系统（例如普通金属）所表现出的行为完全不同。电子相关材料目前是科学技术界非常感兴趣的主题。从科学的角度来看，它们很有趣，因为它们响应温度和磁场的变化而表现出丰富的行为。从技术上讲，这些系统中发现的特性，例如超导性和巨大磁阻，使它们成为未来应用的潜在候选者。该项目是对科学界在国家和国际层面更广泛的凝聚态研究努力的贡献。它将涉及核磁共振技术的应用，以研究含有铀和铈的化合物（例如所谓的重费米子系统以及镍酸镧）中的电子分布特性。重点是阐明随着温度降低，这些材料中可能形成的固有不均匀结构所起的作用。通过该项目，将对本科生和研究生（硕士）学生进行磁共振、射频电子学、低温学和计算机接口技术方面的培训。该项目将与加州大学河滨分校、佛罗里达大学和荷兰 Kamerlingh Onnes 实验室合作开展。***