Conductance of Pd-H Nanojunctions

Abstract

Results of an experimental study of palladium nanojunctions in a hydrogen environment are presented. Two new hydrogen-related atomic configurations are found, which have conductances of $\ensuremath{\sim}0.5$ and $\ensuremath{\sim}1$ quantum unit ($2{e}^{2}/h$). Phonon spectrum measurements demonstrate that these configurations are situated between electrodes containing dissolved hydrogen. The crucial differences compared to the previously studied $\mathrm{P}\mathrm{t}\mathrm{\text{\ensuremath{-}}}{\mathrm{H}}_{2}$ junctions and the possible microscopic realizations of the new configurations in palladium-hydrogen atomic-sized contacts are discussed.