Theory of Metal-Insulator Transitions in Strongly Correlated Electronic Systems with Disorder

无序强相关电子系统中金属-绝缘体转变理论

• 批准号: 0234215
• 负责人: Vladimir Dobrosavljevic
• 金额: $ 24万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234215&HistoricalAwards=false
• 关键词: Theory; Metal; Insulator; Transitions; Strongly

0234215DobrosavljevicThis award supports theoretical and computational research and education on the metal-insulator transition. Several different, but equally important, physical process all play a role; these include the physics of Anderson localization, the effects of strong correlations, and processes associated with glassy freezing of electrons. Energy scales associated with each of these processes are all comparable, so a successful theory must include them all on the same footing. All three basic physical processes associated with the metal-insulator transition can be consistently incorporated within extended dynamical mean-field theory (DMFT) approaches. They are all treated on the same, non-perturbative level allowing a realistic description of many materials. The PI aims to apply extended DMFT methods to several specific systems in an effort to explain phenomena that were beyond the reach of theoretical approaches in the past. Specific topics to be addressed include: (1) Disorder, magnetic field, and doping dependence of the critical behavior in doped semiconductors; (2) Localization effects on magnetic ordering in diluted magnetic semiconductors; (3) The two-dimensional metal-insulator transition viewed as a transition to a Mott-Anderson glass; (4) Non-equilibrium glassy dynamics of electron transport close to metal-insulator transitions; (5) Low temperature spin-glass behavior in electronic Griffiths phases of disordered heavy fermion compounds. In each of these projects, DMFT methods used will be technically tractable and will address the main physical questions. This award supports the integration of research at the forefront of condensed matter science and education at all academic levels: K-12, undergraduate, and graduate. This will be accomplished through participation in various activities, including: Outreach programs - The PI will contribute to enhancing scientific and technological understanding by communicating the importance of his research to the general public through various outreach activities, including lecturing at elementary schools, judging at annual regional Science Fairs, and participating in the FSU Physics Department Open House (PDOP) and the NHMFL Annual Open House activities. Research Experiences for Undergraduates (REU) program - The PI will participate in the REU Site at the NHMFL and plans to provide an opportunity for at least one intern every year to spend two summer months working on one of his research projects. FSU graduate students will be trained - The PI will supervise the research of several physics graduate students in physics. %%%This award supports theoretical and computational research and education on the transition between metallic and insulating states observed in two-dimensional systems, dilute magnetic semiconductors, and some heavy fermion materials. This problem is theoretically challenging in part because it involves different and possibly competing physical processes. The PI will apply and advance a promising avenue of inquiry based on the dynamical mean field theory and its extensions. This award also supports the PI's involvement in a range of education related activities including outreach, undergraduate involvement in the PI's research, and the training of the next generation of condensed matter theorists.***

该奖项支持金属-绝缘体过渡的理论和计算研究以及教育。几种不同但同样重要的物理过程都起着作用；其中包括安德森局域化的物理学，强相关的效应，以及与电子玻璃态冻结相关的过程。与这些过程相关的能量尺度都是可比较的，所以一个成功的理论必须将它们都包含在相同的基础上。与金属-绝缘体跃迁相关的所有三个基本物理过程都可以一致地纳入扩展动态平均场理论（DMFT）方法。它们都是在相同的、非微扰的水平上处理的，允许对许多材料进行现实的描述。PI旨在将扩展的DMFT方法应用于几个特定的系统，以努力解释过去理论方法无法达到的现象。要讨论的具体主题包括：(1)掺杂半导体中关键行为的无序、磁场和掺杂依赖性；(2)稀释磁性半导体中磁有序的局域化效应；(3)二维金属-绝缘体转变被视为向莫特-安德森玻璃的转变；(4)接近金属-绝缘体跃迁的电子输运非平衡玻璃动力学；(5)无序重费米子化合物电子Griffiths相的低温自旋玻璃行为。在这些项目中，所使用的DMFT方法将在技术上易于处理，并将解决主要的物理问题。该奖项支持在所有学术水平（K-12，本科和研究生）的凝聚态科学和教育前沿的研究整合。这将通过参与各种活动来实现，包括：外展计划- PI将通过各种外展活动，包括在小学演讲，在年度区域科学博览会上担任评委，参加FSU物理系开放日（PDOP）和NHMFL年度开放日活动，通过向公众传达其研究的重要性，从而促进科学和技术的理解。本科生研究经验（REU）计划- PI将参加NHMFL的REU网站，并计划每年至少为一名实习生提供两个月的暑期工作机会，从事他的一个研究项目。▽培养外大研究生= PI将指导几名物理学研究生进行物理学方面的研究。该奖项支持在二维系统、稀磁性半导体和一些重费米子材料中观察到的金属和绝缘状态之间转变的理论和计算研究和教育。这个问题在理论上具有挑战性，部分原因是它涉及不同的、可能相互竞争的物理过程。PI将应用和推进基于动态平均场理论及其扩展的有前途的研究途径。该奖项还支持PI参与一系列与教育相关的活动，包括外展，本科生参与PI的研究，以及下一代凝聚态理论家的培训