Structural and transport properties of Nb nanowires

✍ Scribed by Dai, Zhenting ;Zhang, Chun ;Barnett, Robert N. ;Marchenkov, Alexei ;Landman, Uzi

• Book ID: 105364322
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 740 KB
• Volume: 204
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200675362

✦ Synopsis

Abstract

High‐resolution conductance measurements in niobium nanowires below the superconducting transition temperature are presented. Results are shown for a complete multistage elongation‐compression cycle of a nanoscale contact. We focus on a bistability region which manifests itself as random telegraph noise. Density functional structural optimizations and conductance calculations using the non‐equilibrium Green's functions method reproduce and explain the measurements. In particular, the observed bistability is associated with formation of a niobium dimer between the opposing electrodes, with the dimer shuttling between a symmetric, high conductance, and an asymmetric, low conductance, configurations in the gap. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)