Four-atom period in the conductance of monatomic Al wires

Abstract

We present first principles calculations based on density functional theory for the conductance of monatomic Al wires between Al(111) electrodes. In contrast to the even-odd oscillations observed in other metallic wires, the conductance of the Al wires is found to oscillate with a period of 4 atoms as the length of the wire is varied. Although local charge neutrality can account for the observed period it leads to an incorrect phase. We explain the conductance behavior using a resonant transport model based on the electronic structure of the infinite wire.