Quantum interference in atomic-sized point contacts

摘要: The conductance of atomic-sized metallic point contacts is shown to be strongly voltage dependent due quantum interference with impurities even in samples low impurity concentrations. Transmission through these small depends not only on the local atomic structure at contact but also distribution or defects within a coherence length contact. In contrast other mesoscopic systems we show that transport coherent room temperature. use scanning tunneling microscope ~STM! makes it possible fabricate one atom gold whose transmission can controlled by manipulation allowing inelastic spectroscopy such contacts. has been extensively studied relation question quantization. Experimentally, are fabricated stretching using 1 mechanically break junction ~MCBJ!. 2 Theoretically, modeled as constriction for free electrons, 3,4 tight-binding model different arrangements. 5,6 Electronic nanoscopic size structures coherent, and zero bias given Landauer formula 7