Keywords: electrical conductance, quantum wires, coherence transport, cyclic molecular wires, Green', s function, nanostructures, nanotechnology, Iran
Electrical conductance in a typical linear and cyclic quantum wire
Theoretical studies on electrical conductance in nanostructures which consist of two semi-infinite leads separated by a typical molecular wire are carried out within Green's function (GF) formalism in the linear regime. For this reason, the GF of extended molecular wire is obtained. Hence, the electrical conductance of the system is derived theoretically, using the GF elements and wire self-energies, within the tight-binding approach and in the ballistic regime. Based on this formalism, the electrical conductance of a linear molecular wire such as poly-acetylene is calculated. The results show that for this chain, a gap appears in the band structure. Moreover, the formalism is generalised to the quasi one dimensional chain such as cyclic benzene wires attached to the metallic leads in the cis and trans classes. Our results show that in the trans class, the conductance of benzene chain decreases as increases the length of the chain.