REPORTS Properties of Metallic Nanowires: From Conductance Quantization to Localization

Material structures of reduced dimensions exhibit electrical and mechanical properties different from those in the bulk. Measurements of room-temperature electronic transport in pulled metallic nanowires are presented, demonstrating that the conductance char-acteristics depend on the length, lateral dimensions, state and degree of disorder, and elongation mechanism of the wire. Conductance during the elongation of short wires(length e- ~ 50 angstroms) exhibits periodic quantization steps with characteristic dips, correlating with the order-disorder states of layers of atoms in the wire predicted by molecular dynamics simulations. The resistance R of wires as long as e- ~ 400 angstroms exhibits localization characteristics with In R(()- ~ e2. Material systems of reduced size or dimen-sionality may, and often do, exhibit proper-ties different from those found in the bulk. These include quantized conductance (1, 2) in point contacts and narrow channels whose characteristic (transverse) dimen-sions approach the electronic wavelength