The electronic structure and related physical properties of correlated electron systems

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Strongly correlated electron systems exhibit some of the most interesting physical properties important for present and future applications in electronic devices, sustainable energy, biomedical devices, transportation and perhaps even quantum computing. Materials made of transition metal and rare earth compounds such as their oxides are examples often exhibiting extreme properties such as high temperature superconductivity, high thermoelectric power, high dielectric constants, colossal magneto resistance and many more. These materials are different from conventional semiconductors like Si or simple metals like Al in which the charge of the electrons moving in amongst atoms plays the important role in determining the applications. Transition metal oxides often are electrical insulators and magnetic because of the strong repulsive interaction between the electrons. However chemical substitution can turn such magnetic insulators into high temperature superconductors (Nobel Prize 1988) and cause other dramatic changes in their properties. The basic physics governing their behaviour remains one of the biggest intellectual challenges of modern scientific research. Here the spin and orbital degrees of freedom and their interplay with the charge degrees of freedom of electrons play essential roles. With the recent development of the physical preparation of new oxide materials using an atom by atom deposition approach completely new materials and properties based on interfaces have been demonstrated opening up a new direction in material science and device applications. We will utilize the new experimental facilities we developed at UBC and the Canadian Light source for resonant X ray scattering and in situ atom by atom material preparation and apply these together with new theoretical insights to the study of surfaces, engineered interfaces and nanostructures of strategically selected transition metal oxides. This new facility is especially suited to study the electronic structure of buried interfaces which are hard or impossible to access in a non destructive manner with other methods. The spectacular properties found at such interfaces are predicted to potentially form a whole new platform for the next generation of electronic devices.