Different wavelength oscillations in the conductance of 5d metal atomic chains

Combining ab-initio and self-consistent parametrized tight-binding calculations we analyze the conductance properties of atomic chains of 5d elements like Au, Pt and Ir. It is shown that, in addition to the even-odd parity oscillations characteristic of Au, conduction channels associated with the almost full d bands in Pt and Ir give rise to longer periods which could be observed in sufficiently long chains. The results for short chains are in good agreement with recent experimental measurements.