NMR Studies of Nanoscale Electronic Inhomogeneity in Strongly Correlated Electron Systems

*非技术摘要*在过去的半个世纪里，对材料的基本理解的发展推动了重大的技术进步。晶体管、计算机和固态存储设备基于相对简单的固态系统，如硅，其电子特性在原子级别进行控制。更复杂的材料，如高温超导体，为未来的新技术提供了巨大的潜力，但为了取得进展，我们必须了解和控制这些系统中电子之间的强烈相互作用。事实上，现代物理学的一个重大挑战是从根本上理解具有强烈电子相互作用的新材料中出现的意想不到的行为和现象。这些现象的一个关键方面是电子密度在微观长度尺度(纳米尺度)上变得空间相关。这一个人研究人员奖支持一个项目，目的是通过使用尖端磁共振技术系统地成像几类材料的磁和电荷空间变化，确定出现这些不均匀的条件和潜在机制。随着我们对这些材料的了解的增加，这些研究可能会导致未来新技术的发展。该项目将支持博士生的教育，并将重振美国与亚洲和欧洲的竞争力，在亚洲和欧洲，类似的努力已经确立并正在增长。*技术摘要*这一个人研究人员奖支持一个项目，目的是确定在强相互作用的凝聚态物质中出现电子密度的静态纳米级变化的条件和潜在机制。与电子本质上不相互作用的硅相反，强关联材料中的电子表现出无法预先预测的意想不到的行为和紧急现象。对这些材料的基态和激发态的基本了解是凝聚态物理学的重大挑战之一，对于新材料的设计和功能至关重要，也是国际上巨大研究努力的重点。核磁共振将被用来系统地探测几个相关电子系统中的非均匀电子态，以提供关于块体中自旋和电荷不均匀的纳米尺度空间关联的详细信息。这些实验将解决凝聚态物理学中一些最基本和最有争议的问题，这些问题涉及过渡金属氧化物、重费米子和烟酸铁超导体中出现的非均匀电子态的性质。随着我们对这些材料的了解的增加，这些研究可能会导致未来新技术的发展。该项目将支持博士生在这些先进技术方面的教育，并将重振美国与亚洲和欧洲的竞争力，在亚洲和欧洲，类似的努力已经确立并在不断增长。

****NON-TECHNICAL ABSTRACT****Major technological advances over the last half-century have been fueled by the development of a fundamental understanding of materials. Transistors, computers, and solid state memory devices are based on relatively simple solid state systems like silicon whose electronic properties are controlled at the atomic level. More complex materials such as high temperature superconductors hold tremendous potential for new technologies in the future, yet in order to make progress we must understand and control the strong interactions between the electrons in these systems. Indeed, one grand challenge of modern physics is a fundamental understanding of the unexpected behavior and phenomena that emerge in new materials with strong electronic interactions. A key aspect of these phenomena is that the electron density becomes spatially dependent at a microscopic length scale (nanoscale). This individual investigator award supports a project with a goal of identifying the conditions and underlying mechanisms under which these inhomogeneities emerge by systematically imaging the magnetic and charge spatial variations across several classes of materials using cutting edge magnetic resonance techniques. Along with increasing our understanding of these materials, the research may lead to the development of new technologies in the future. This project will support the education of a PhD student, and will revitalize US competitiveness with Asia and Europe where similar efforts are well established and growing. ****TECHNICAL ABSTRACT****This individual investigator award supports a project with the goal of identifying the conditions and underlying mechanisms under which static nanoscale variations in electronic density emerge in strongly interacting condensed matter. In contrast to silicon, where electrons are essentially noninteracting, electrons in strongly correlated materials exhibit unexpected behaviors and emergent phenomena which cannot be predicted a priori. A fundamental understanding of the ground and excited states of these materials is one of the grand challenges of condensed matter physics, is critical for the design and functionality of new materials, and is the focus of a tremendous international research effort. Nuclear Magnetic Resonance (NMR) will be used to systematically probe the inhomogeneous electronic states in several correlated electron systems to provide detailed information about the nanoscale spatial correlations of the spin and charge inhomogeneities in the bulk. These experiments will address some of the most fundamental and hotly contested issues in condensed matter physics concerning the nature of the inhomogeneous electronic states that emerge in the transition metal oxides, the heavy fermions, and the ferropnictide superconductors. Along with increasing our understanding of these materials, the research may lead to the development of new technologies in the future. This project will support the education of a PhD student in these advanced technologies, and will revitalize US competitiveness with Asia and Europe where similar efforts are well established and growing.