Transition Voltage Spectroscopy and the Nature of Vacuum Tunneling
  Transition Voltage Spectroscopy (TVS) has been proposed as a tool to analyze charge transport through molecular junctions. We extend TVS to Au-vacuum-Au junctions and study the distance dependence of the transition voltage V_t(d) for clean electrodes in cryogenic vacuum. On the one hand, this allows us to provide an important reference for V_t(d)-measurements on molecular junctions. On the other hand, we show that TVS forms a simple and powerful test for vacuum tunneling models. 
M.L. Trouwborst, C.A. Martin, R.H.M. Smit, C.M. Guedon, T.A. Baart,   S.J. van der Molen, and J.M. van Ruitenbeek
cond-mat.mes-hall