Even-odd conductance oscillation in atomic wires

The linear response conductance is computed in a one-dimensional atomic wire between two adiabatically expanding metal electrodes. We show that the conductance behavior is significantly different from that of a mesoscopic narrow channel. Specifically, we find that the conductance of such an atomic wire oscillates periodically between quantum unit of conductance Go for odd number of atoms in the wire and rG(Q)(r < 1) for even number of atoms. This even-odd oscillation is very robust and should be observable at room temperature. (C) 1997 Published by Elsevier Science Ltd.