Quantum suppression of shot noise in atom-size metallic contacts
  The transmission of conductance modes in atom-size gold contacts is investigated by simultaneously measuring conductance and shot noise. The results give unambiguous evidence that the current in the smallest gold contacts is mostly carried by nearly fully transmitted modes. In particular, for a single-atom contact the contribution of additional modes is only a few percent. In contrast, the trivalent metal aluminum does not show this property. 
H.E. van den Brom and J.M. van Ruitenbeek (Leiden University)