Non-equilibrium quasiparticles and topological excitations in hybrid superconducting structures

We discuss the properties of a hybrid single electron turnstile, involving a small superconducting island sandwiched between normal metal leads. We theoretically model the charge transport and non-equilibrium quasiparticle distribution and compare with recent experimental findings. In the second part of the thesis we theoretically investigate chains of magnetic atoms on top of superconducting substrates and discuss the ability of the hybrid setup to harbor Majorana fermion excitations.