Structure and conductance of a gold atomic chain

The conductances of linear chains of gold atoms suspended between two electrodes were calculated while the distance between the electrodes was increased. The stable structures of the linear chains of the gold atoms at low temperature were initially determined by using the ab initio local spin-density-functional approach. As the average bond length $〈d〉$ increased, the spacings of the neighboring gold atoms modulated similarly to the Peierls transition. The maximum tensile force of a linear four-atom-chain was 0.91 nN and occurred at $〈d〉\approx 3.1$ Å. The electric conductances were then calculated using the recursion transfer-matrix method. The calculation indicated that the conductance at the Fermi level of the modulated chain decreased from ${1G}_0{(=2e}^2/h)$ as the chain was stretched.