Complex Behavior Near the Metal-Insulator Transition

该奖项支持介于金属和绝缘体之间的材料的理论和计算研究和教育。在这种状态下，材料的性质很容易调整，在这种状态下，几个可能的基态相互竞争。在这里，大多数物理量表现出不寻常的行为，并且证明很难用传统的思想和方法来解释。最近的实验揭示了空间不均匀性的显著影响。在某些情况下，中间不均匀相可能出现在金属和绝缘体之间，甚至可能没有无序。这种复杂性是金属-绝缘体过渡区的新范式。PI将使用先进的计算和理论技术开展一项全面的研究计划，以促进对该制度中基本物理过程的理解，包括：(1)Mott和Anderson路线的相互作用定位，以及金属-绝缘体转变之前的电子Griffiths相的性质；(2) Ruderman-Kittel-Kasuya-Yosida和Kondo单线态的竞争是抑制费米液体相干性的机制；(3)在掺杂驱动的金属-绝缘体跃迁中，远距离库仑相互作用和电荷排序作为Wigner-Mott局域化的驱动力的作用。基于动态平均场理论及其扩展的方法将用于开展研究。该项目将培养理论和计算凝聚态物理方面的研究生。PI将继续通过外展活动，促进和提高公众对科学技术的理解和我们研究的重要性，包括：在小学举办讲座，普及科学技术，让最年轻的人能够接触到最新的发现；担任年度区域科学展览的评委；并参加了FSU物理系和NHMFL年度开放日活动。PI将在开发一项名为“新兴实验室”（Emergent Labs）的重大新拓展计划中发挥主导作用，该计划旨在将凝聚态科学的前沿研究发现直接带入初中和高中教师的课堂。该奖项支持介于金属和绝缘体之间的材料的理论和计算研究和教育。PI将使用先进的计算技术来研究具有电子的材料，这些电子相互作用强烈，并且在其结构或化学中包含许多缺陷，这些缺陷会在电子的环境中反映出来。在一定条件下，增加导电材料中的缺陷和不完美的数量可以使其变成绝缘体。最近的实验表明，在一些材料中，这不是一个简单的转变，而是从金属到绝缘体的过程要经过复杂的“坏金属”状态。PI将使用先进的计算方法来研究这些状态的性质，目的是了解电子之间强相互作用的作用，以及这种转变在块状材料或单层材料中有何不同。这是一项基础研究，旨在了解金属、绝缘体的性质，以及它们之间可能存在的电子物质的新状态。这项研究可能有助于未来器件技术的知识基础，并开发新的策略来发现具有理想电子特性的新材料。该项目将培养理论和计算凝聚态物理方面的研究生。PI将继续通过外展活动，促进和提高公众对科学技术的理解和我们研究的重要性，包括：在小学举办讲座，普及科学技术，让最年轻的人能够接触到最新的发现；担任年度区域科学展览的评委；并参加了FSU物理系和NHMFL年度开放日活动。PI将在开发一项名为“新兴实验室”（Emergent Labs）的重大新拓展计划中发挥主导作用，该计划旨在将凝聚态科学的前沿研究发现直接带入初中和高中教师的课堂。

TECHNICAL SUMMARYThis award supports theoretical and computational research and education on materials that are somewhere between metals and insulators. Material properties are easy to tune in this regime, where several possible ground states compete. Here most physical quantities display unusual behavior, and prove difficult to interpret using conventional ideas and approaches. Recent experiments reveal the significant effects of spatial inhomogeneities. In some cases, intermediate heterogeneous phases may emerge between the metal and the insulator, possibly even in absence of disorder. Such complexity emerges as a new paradigm of the metal-insulator transition region. The PI will carry out a comprehensive research program using advanced computational and theoretical techniques to advance understanding of fundamental physical processes in this regime, including: (1) the interplay of Mott and Anderson routes to localization, and the properties of electronic Griffiths phases preceding the metal-insulator transition; (2) the competition of Ruderman-Kittel-Kasuya-Yosida and Kondo singlets as a mechanism to suppress Fermi liquid coherence; (3) the role of the long-range Coulomb interaction and charge ordering, as a driving force for Wigner-Mott localization in doping-driven metal-insulator transitions. Methods based on dynamical mean-field theory and its extensions will be used to carry out the research.This project will train graduate students in theoretical and computational condensed matter physics. The PI will continue to promote and enhance scientific and technological understanding and importance of our research to the general public through outreach activities, including: presenting lectures at elementary schools in order to popularize science and technology, and to bring the most recent discoveries within reach of the youngest; acting as a Judge at annual Regional Science Fairs; and participating in the FSU Physics Department and the NHMFL Annual Open House activities. The PI will provide a leading role in developing a major new outreach initiative called the Emergent Labs which aims to take cutting-edge research discoveries in condensed matter science directly into the classrooms of middle and high school teachers. NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on materials that are somewhere between metals and insulators. The PI will use advanced computational techniques to study materials which have electrons that interact strongly with each other and contain many imperfections in their structure or chemistry that are reflected in the environment of the electrons. Under certain conditions, increasing the number of defects and imperfections in a conducting material can turn it into an insulator. Recent experiments suggests that in some materials this is not a simple transformation, but rather the route from metal to insulator proceeds through complicated "bad metal" states. The PI will use advanced computational methods to investigate the nature of these states with an aim to understand the role of the strong interactions between electrons and how this transformation differs in bulk materials or in a single layer.This is fundamental research to understand the nature of metals, insulators, and new states of electronic matter that may exist between them. This research may contribute to the intellectual foundations of future device technologies and to developing new strategies to discover new materials with desired electronic properties. This project will train graduate students in theoretical and computational condensed matter physics. The PI will continue to promote and enhance scientific and technological understanding and importance of our research to the general public through outreach activities, including: presenting lectures at elementary schools in order to popularize science and technology, and to bring the most recent discoveries within reach of the youngest; acting as a Judge at annual Regional Science Fairs; and participating in the FSU Physics Department and the NHMFL Annual Open House activities. The PI will provide a leading role in developing a major new outreach initiative called the Emergent Labs which aims to take cutting-edge research discoveries in condensed matter science directly into the classrooms of middle and high school teachers.