Quantum Transport in Carbon-based Nanostructures: Theory and Computational Methods

The electronic structure and the quantum transport properties of graphene, carbon nanotubes and graphene nanoribbons are studied using analytical and numerical tools, taking special care in considering fundamental questions of high experimental relevance and in relating the results to experiments. Based on the tight-binding description of electrons and integrating the results of microscopic ab initio calculations as well as several minimal models at various degrees of detail, the Landauer formalism of linear conductance is applied in combination with Green function decimation algorithms for the efficient handling of large systems of up to thousands of atoms. Following a detailed theoretical introduction, the work covers the effects of realistically modelled metallic contacts on the transport properties of nanotubes and -ribbons, ballistic magnetoresistance effects, the mesoscopic length scales in disordered and defective carbon systems, multilayer carbon systems, issues of approximate momentum conservation in incommensurate systems and the effects of external magnetic fields on the electronic structure of carbon systems.