Resistance of atomic wires

The resistance of wires consisting of 1-3 atoms connecting two semi-infinite metallic electrodes is calculated for both small and large bias. The wires discussed consist of Al atoms, with one of the Al atoms substituted by S in certain cases. The resistances obtained are in the range 7-∼30 kΩ. For the three-atom wire, the value of the resistance when the S atom is present depends on the order of the atoms in the wire. When the S is an end atom, the resistance at larger bias also shows a dependence on polarity (diode behavior). These studies involve a self-consistent calculation of the electron density distribution for the entire electrode/wire system. © 1995 The American Physical Society.