title: Probing the orbital origin of conductance oscillations in atomic chains.
abstract: We investigate periodical oscillations in the conductance of suspended Au and Pt atomic chains during elongation under mechanical stress. Analysis of conductance and shot noise measurements reveals that the oscillations are mainly related to variations in a specific conduction channel as the chain undergoes transitions between zigzag and linear atomic configurations. The calculated local electronic structure shows that the oscillations originate from varying degrees of hybridization between the atomic orbitals along the chain as a function of the zigzag angle. These variations are highly dependent on the directionally and symmetry of the relevant orbitals, in agreement with the order-of-magnitude difference between the Pt and Au oscillation amplitudes observed in experiment. Our results demonstrate that the sensitivity of conductance to structural variations can be controlled by designing atomic-scale conductors in view of the directional interactions between atomic orbitals.
authors.affiliation: Department of Chemical Physics and ‡Department of Materials and Interfaces, Weizmann Institute of Science , Rehovot 76100, Israel.
authors.forename: Ran
authors.initials: R
authors.lastname: Vardimon
authors.forename: Tamar
authors.initials: T
authors.lastname: Yelin
authors.forename: Marina
authors.initials: M
authors.lastname: Klionsky
authors.forename: Soumyajit
authors.initials: S
authors.lastname: Sarkar
authors.forename: Ariel
authors.initials: A
authors.lastname: Biller
authors.forename: Leeor
authors.initials: L
authors.lastname: Kronik
authors.forename: Oren
authors.initials: O
authors.lastname: Tal