Quantum transport in nanostructures [Elektronische Ressource] : from computational concepts to spintronics in graphene and magnetic tunnel junctions / vorgelegt von Michael Wimmer

This dissertation deals with advanced compu-tational concepts for quantum transport and spintronics in graphene and magnetic tunnel junctions.The first part is devoted to developing generic transport algorithms, applicable to any tight-binding Hamiltonian. After a review of Green‘s function based quantum transport formalisms, the dissertation presents a numerically stable algorithm for computing the surface Green‘s function of a lead, as well as a generalized Fisher-Lee relation. A matrix reordering algorithm is introduced to extend the applicability of established quantum transport algorithms.Michael WimmerThe second part discusses spin-dependent transport in magnetic tunnel junctions and Quantum transport in nano- graphene nanoribbons, making use of the numerical techniques developed in the first structures: From computational part as well as analytical models. In particular, this includes an investigation of the tunneling concepts to spintronics in anisotropic magnetoresistance in a strong magnetic field, a thorough discussion of the graphene and magnetic tunnel transport in the graphene edge state, and a study of spin currents in rough graphene nanoribbons.