Quasiparticle dynamics of inhomogeneous superconducting and spin-orbit coupledsystems

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Within the proposed project we aim to investigate the following topics:(a) Investigation of spectral properties of strongly disordered superconductors. Since several years such systems are in the focus of scientific interest due to the superconducting-insulator transition which may be realized at strong disorder. One finds a segregation of the superconducting state into nanometer size islands where first local pairing is realizedbefore at lower temperatures and depending on the disorder strength a coherent superconducting state may be realized. Within the proposed project we aim to calculate the influence of collective excitations on the spectral properties of these systems and therefore contribute to an understanding of the superconductor-insulator phase transition.(b) Investigations related to spin-charge conversion at oxide interfaces. The observed metallic conductivity between the two band insulators strontium titanate and lanthanum aluminate bears interesting scientific questions but also strong potential for technical applications.These systems are characterized by a strong spin-orbit coupling which makes them suitable for spintronics applications. In fact, recent experiments have demonstrated a large efficiencyfor the conversion of a non-equilibrium spin polarization into an electric current. Our project aims to understand this so-called spin-galvanic at oxide interfaces effect based on a microscopic model. Besides an adequate implementation of the bandstructure and atomic spin-orbit coupling it is also necessary to include the effect of disorder. Our investigations arealso planned to be extended to the spin-Hall effect which describes the conversion of a spin current into an electric current.