title: Lifetime analysis of individual-atom contacts and crossover to geometric-shell structures in unstrained silver nanowires.
abstract: We study the crossover of quantum point contacts from (i) individual-atom contacts to (ii) electronic-shell effects and finally to (iii) geometric-shell effects in electrochemically deposited silver contacts. The method allows the fabrication of mechanically unstrained structures, which is a requirement for determining the individual atomic configuration by means of a detailed lifetime analysis of their conductance. Within the geometric-shell model, the sequence of conductance maxima is explained quantitatively based on the crystal structure data of silver, and the growth mechanism of the nanowires is discussed.
authors.affiliation: Institute of Applied Physics and Center for Functional Nanostructures (CFN), University of Karlsruhe, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Obermair
authors.forename: Holger
authors.initials: H
authors.lastname: Kuhn
authors.forename: Thomas
authors.initials: T
authors.lastname: Schimmel