Topology effects on local electronic properties and on the conductance of molecular structures

Electronic and transport properties of a class of low-dimensional systems are investigated within the Green-function formalism by adopting general real-space renormalization techniques. The effects of the lattice topology (coordination, dimension and structure) on the local density of states are discussed, mainly for energies close to the Fermi energy. An effective band gap is inferred by conductance calculations of molecular hybrid systems composed of a molecular wire and carbon nanotubes using the latter as metallic leads. An oscillatory behavior is found as a function of the interface number of links. Such theoretical analysis may certainly be useful for designing devices based on low-dimensional networks.