Electronic transport theory of the spin-dependent proximity effect in superconductor-ferromagnet heterostructures

PhD Thesis by Dr. Peter Machon, including a full introduction to the quasi-classical Green's function Theory for conventional superconductors, and the Keldysh technique for non-equilibrium physics, with selected proofs and citations. Further, including an introduction to the quantum circuit theory, a finit element approach for the Usadel equation. The articles discuss extensions of the circuit theory, four special examples, and a general numerical solution algorithm. In detail: - The extension of the circuit theory to spin dependent Systems, to describe superconductor-(strong)ferromagnet hybrid structures. - The differential conductance of a ferromagnetic insulator - superconductor heterostructure (with experiments), showing huge spin-mixing angles. - The local and the nonlocal thermoelectric effect of two and three terminal structures, with a generalization of the Onsager reciprocity relation. - The giant thermoelectric effect in stacked and transistor-like structures of superconductors and ferromagnets/ferromagnetic insulators, including a large figure of merit (>1.75). - The local differential conductance and search for equal spin triplet pairing in a superconductor - ferromagnetic insulator - normal stacked structure (with experiment). - The generalized solution strategy of the discrete Usadel equation and the BCS self-consistency relation, including a description (with diagram) of the numerical implementation, with physical and numerical optimization techniques.