Correlation of geometrical and electronic properties in metallic nanowires

摘要

The structure on the atomic scale was found to be directly correlated with the electronic and transport properties of ultrathin metallic wires.Wepresent examples of both self-organized and artificially structured nanowires in the system Pb/Si(557). We demonstrate that artificial structuring on the nanoscale allows identification and determination of the electrical transport properties of atomic size defects, using Si(557) as a quasiinsulating substrate and a Si double step in a monolayer high Pb nanowire as an example. One-dimensional (1D) properties with strong electron correlation and various instabilities in metallic chains or ribbons generated by metal adsorption of submonolayers on insulating substrates like Si(111) or Si(557) turn out to always be modified by the unavoidable coupling to 2D and 3D. The wealth of new and partly unexpected phenomena is exemplified here again in monolayers of Pb on Si(557), which forms wire-like arrays. We identify structural self-stabilization as the origin of 1D electronic transport and show that a new 1D state is generated by step decoration. Magnetoconductance measurements yield even deeper insight into mechanisms of electronic transport, as also exemplified in this specific system.