Title: Electrical conductance in a typical linear and cyclic quantum wire

Authors: Mohammad Mardaani, Ali A. Shokri

Addresses: Physics Group, Faculty of Science, Shahrekord University, P.O. Box 115, Shahrekord, Iran; Computational Physical Sciences Research Laboratory, Department of Nano-Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-5531, Tehran, Iran. ' Department of Physics, Payame Noor University (PNU), Nejatollahi St. 159995-7613, Tehran, Iran; Computational Physical Sciences Research Laboratory, Department of Nano-Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-5531, Tehran, Iran

Abstract: 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.

Keywords: electrical conductance; quantum wires; coherence transport; cyclic molecular wires; Green|s function; nanostructures; nanotechnology; Iran.

DOI: 10.1504/IJNT.2009.027567

International Journal of Nanotechnology, 2009 Vol.6 No.10/11, pp.1050 - 1061

Published online: 31 Jul 2009 *

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