Length dependence of the electronic and structural properties of monoatomic gold wires

Abstract

The electronic structure and stability of monoatomic gold wires of different lengths have been studied by the projector augmented-wave method (PAW) within the density functional theory (DFT). The results show that the wire stability steadily decreases when the number of incorporated atoms increases. The wire tends to deviate from a linear configuration and the structural distortions increase upon both stretching and an increasing number of atoms. The electronic structure of the wires with an odd number of atoms exhibits an $s$-state conduction channel, whereas an even number of atoms opens up a band gap at the Fermi level. These odd-even oscillations are determined by the filled shell effect, which alters the dominating orbital character at the top of the valence band from $s$ (in the case of an unfilled $s$-shell and an odd number of atoms) to $d$ (in the case of the filled $s$-shell and an even number of atoms).