Conduction Channels of One-Atom Zinc Contacts
  We have determined the transmission coefficients of atomic-sized Zn contacts using a new type of breakjunction which contains a whisker as a central bridge. We find that in the last conductance plateau the transport is unexpectedly dominated by a well-transmitting single conduction channel. We explain the experimental findings with the help of a tight-binding model which shows that in an one-atom Zn contact the current proceeds through the 4s and 4p orbitals of the central atom. 
M. H\"afner, P. Konrad, F. Pauly, J.C. Cuevas and E. Scheer