Ballistic conductance of oxygen and sulfur-incorporated zigzag Au atomic wires

Abstract

We study the effects of oxygen and sulfur impurity atoms on the electronic structure and ballistic conductance of zigzag-shaped Au monoatomic wires by a first-principles calculation based on the embedded Green's-function technique. In contrast to the straight wires in which the $\mathrm{O}\phantom{\rule{0.2em}{0ex}}2p$ $(\mathrm{S}\phantom{\rule{0.2em}{0ex}}3p)$ states form doubly degenerate sharp $\ensuremath{\pi}$ resonant levels at the Fermi energy $({E}_{F})$, one of them is broadened due to symmetry lowering accompanied by zigzag deformations, shifts to lower energies, and exhibits a Fano-type resonance dip in the ballistic conductance. The other state, which does not couple with the $\mathrm{Au}\phantom{\rule{0.2em}{0ex}}6s$-like band, remains a sharp resonant peak at ${E}_{F}$ in the density of states and in the conductance. It splits into two peaks corresponding to majority and minority spin electrons when spin polarization is taken into consideration.