Computational study of conductance through Cu, Ag, Au and Pt atomic chain contacts

Abstract

Atomic size wires are basic devices of molecular electronics and a common model for simulation of transport properties of other molecular devices, where hypothetical semi-infinite equidistant atomic chains are considered as electrodes. In this work, structure of infinite linear Cu, Ag, Au and Pt atomic chains was studied at nonrelativistic, scalar and spin–orbit zeroth order relativistic approximation levels. Bonds in chains were characterized within Quantum Theory of “Atoms In Molecules” approach. Conductance through finite chains of six atom length between bulk leads for bias voltage range of 0.0–1.0 V was calculated within non-equilibrium Green’s function approach combined with density functional theory. Chain conductance at high bias voltages correlates with product of Jenkins’ metallicity and positively defined kinetic energy density at bond critical points of corresponding infinite atomic chains. Variation of number of atoms in finite Au and Pt chains showed weak “odd-even” oscillations of chain conductance at some bias voltages.