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

点击翻译按钮获取中文摘要

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.