Observation of a parity oscillation in the conductance of atomic wires

TL;DR

This study observes a universal parity oscillation in the conductance of atomic wires of Au, Pt, and Ir, indicating a fundamental property of atomic-scale conductance during chain formation.

Contribution

It demonstrates the presence of parity oscillations in multiple metals, extending previous predictions to a broader range of atomic wires.

Findings

Conductance oscillates with even or odd atom numbers during chain formation.

Parity oscillation observed in Au, Pt, and Ir atomic wires.

Universal feature of atomic wires suggested by results.

Abstract

Using a scanning tunnel microscope or mechanically controlled break junctions, atomic contacts of Au, Pt and Ir are pulled to form chains of atoms. We have recorded traces of conductance during the pulling process and averaged these for a large amount of contacts. An oscillatory evolution of conductance is observed during the formation of the monoatomic chain suggesting a dependence on even or odd numbers of atoms forming the chain. This behaviour is not only present in the monovalent metal Au, as it has been previously predicted, but is also found in the other metals which form chains suggesting it to be a universal feature of atomic wires.