Conductance fluctuations as a tool for investigating the quantum modes in atomic-size metallic contacts

Recently it has been observed that the conductance fluctuations of atomic-size gold contacts are suppressed when the conductance is equal to an integer multiple of the conductance quantum. The fact that these contacts lend to consist exclusively of fully open or closed modes has been argued to be the origin for this suppression. Here the experiments have been extended to a wide range of metallic elements with different chemical valences, and they provide information about the relation between the mode composition and statistically preferred conductance values observed in conductance histograms.