EVOLUTION OF CONDUCTING CHANNELS IN METALLIC ATOMIC CONTACTS UNDER ELASTIC-DEFORMATION

We investigate both experimentally and theoretically the evolution of conductance in metallic one-atom contacts under elastic deformation. W hile simple metals like An exhibit almost constant conductance plateau s, Al and Pb show inclined plateaus with positive and negative slopes. It is shown how these behaviors can be understood in terms of the orb ital structure of the atoms forming the contact. This analysis provide s further insight into the issue of conductance quantization in metall ic contacts revealing important aspects of their atomic and electronic structures.