Tools for conductance measurements of metallic and molecular nanowires

International audience; Conductance-elongation curves of gold nanojunctions exhibit characteristic plateaus just prior to breaking. Conductances of these plateaus are integer multiples of the quantum of conductance. These plateaus occur because, in this size regime, transport is ballistic and the conductance is independent of the length of the nanojunction. We developed a STM-based break junction technique to access to the conductance-elongation curves. In this paper, specific tools adapted for measurements in solution are described. We then report on our results obtained for both metallic and molecular nanowires.