Conductance of Pb on modified Si(3Â 3Â 5) vicinal surface

Using the four-point probe method in UHV condition the conductance through a Si(3 3 5)-Au vicinal surface with deposited 6 ML of Pb is investigated in situ during the chain formation process, i.e. as a function of temperature. For the critical temperature, Tc=220K, a local minimum in the conductance is observed which is related to the structural transition of Pb from a two-dimensional film to one-dimensional chains. This process is confirmed by the RHEED technique. To describe theoretically the conductance behavior a tight-binding approach and the Green's function technique are applied and a satisfactory qualitative agreement with experimental results is obtained.