Effect of metal-molecule contact on electron-vibration interaction in single hydrogen molecule junction

The effect of the strength of metal-molecule contact on electron-vibration interaction was investigated for the single hydrogen molecule bridging between Cu electrodes and Pt electrodes. For the single hydrogen/Pt junctions, conductance suppression caused by electron-vibration interaction was observed only for the junction with a conductance value above 0.5 G(0)(G(0) = 2e(2)/h), which corresponded with the prediction of the one-level model in the symmetric coupling of the molecule to metal electrodes. In contrast, conductance suppression was also observed for the single hydrogen/Cu junctions with a conductance value below 0.5 G(0), which could be explained by a decrease in the interaction between the hydrogen molecule and the Cu electrodes.