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: 9974311
• 负责人: Vladimir Dobrosavljevic
• 金额: $ 15万
• 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: 1999
• 资助国家: 美国
• 起止时间: 1999-07-15 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9974311&HistoricalAwards=false
• 关键词: Theory; Metal; Insulator; Transitions; Strongly

9974311DobrosavljevicThis grant will support theoretical research into a theory of metal-insulator transitions, with an emphasis on incorporating both strong electron-electron interactions and disorder. A dynamical mean-field approach to disordered interacting electrons, which has previously been applied to transition-metal oxides, heavy-fermion systems, and Kondo insulators, will be extended to treat metal-insulator transitions with strong disorder and strong correlations. This approach will provide a simple order-parameter description of the problem, and will be used to construct equations of state for thermodynamic and transport properties valid over a broad range of temperatures, carrier concentrations, and amounts of disorder. Within this framework, specific problems involving transport near Mott-Anderson transitions, non-Fermi liquid behavior in strongly disordered metals, high temperature anomalies, and the effects of glassy behavior on metal-insulation transitions will be studied. The results will be of direct relevance to many systems, including doped semiconductors, disorder heavy-fermion systems, layered ruthenates and manganites, two-dimensional electron gases, and high-temperature superconductors.Recent years have witnessed renewed interest in a long-standing problem of metal-insulator transitions, with the traditional models of Mott and Anderson emphasizing the roles of electron correlations and local disorder, respectively. Many new materials with technological significance have electronic properties exhibiting both strong electron-electron interactions and disorder, which is difficult to analyze using convention theoretical tools. This grant supports research into the development and application of a new approach that can incorporate both of these relevant processes. This work will provide a simple order-parameter description of the problem, and will be used to construct equations of state for thermodynamic and transport properties valid over a broad range of temperatures, carrier concentrations, and amounts of disorder. This approach should make it possible to incorporate all the basic mechanisms of localization, including both the Mott and Anderson route, as well as the possibility of glassy freezing of electrons. The results will be of direct relevance to many systems, including doped semiconductors, disorder heavy-fermion systems, layered ruthenates and manganites, two-dimensional electron gases, and high-temperature superconductors. The formalism can be adapted to many realistic situations and should open new avenues for the development of materials science research.

9974311 Dobrosavljevic该补助金将支持理论研究到金属-绝缘体转变的理论，重点是结合强电子-电子相互作用和无序。 一个动态的平均场方法无序相互作用的电子，这是以前被应用到过渡金属氧化物，重费米子系统，近藤绝缘体，将扩展到治疗金属-绝缘体过渡与强无序和强关联。 这种方法将提供一个简单的顺序参数描述的问题，并将被用来构建状态方程的热力学和运输性能有效的温度范围很广，载流子浓度和数量的障碍。在这个框架内，具体的问题，涉及交通附近的莫特-安德森转变，非费米液体行为在强烈无序的金属，高温异常，以及玻璃态行为对金属绝缘转变的影响将进行研究。 这些结果将直接关系到许多系统，包括掺杂半导体，无序重费米子系统，层状层状介电体和锰氧化物，二维电子气和高温超导体。近年来，人们对金属-绝缘体相变这一长期存在的问题重新产生了兴趣，Mott和安德森的传统模型分别强调了电子关联和局域无序的作用。 许多具有技术意义的新材料具有电子性质，表现出强烈的电子-电子相互作用和无序性，这是很难用常规理论工具分析的。 这项赠款支持研究开发和应用一种新的方法，可以将这两个相关的过程。这项工作将提供一个简单的顺序参数描述的问题，并将被用来构建状态方程的热力学和运输性能有效的温度范围很广，载流子浓度和数量的障碍。 这种方法应该能够结合所有的基本机制的本地化，包括莫特和安德森路线，以及玻璃冻结的电子的可能性。结果将直接关系到许多系统，包括掺杂的半导体，无序重费米子系统，层状的manganites和manganites，二维电子气体，高温超导体。 这种形式主义能适应许多实际情况，为材料科学研究的发展开辟了新的途径。