Single-Co Kondo effect in atomic Cu wires on Cu(111)

TL;DR

This study investigates how the single-Co Kondo effect varies in atomic Cu chains on Cu(111), revealing resonance quenching in specific configurations through experimental assembly and first-principles calculations.

Contribution

It demonstrates the controlled assembly of atomic chains with a single magnetic atom and explores the evolution of the Kondo effect with atomic configuration.

Findings

Kondo resonance varies with chain composition and length.

Resonance is quenched in specific Cu-Co-Cu clusters.

First-principles calculations support experimental observations.

Abstract

Linear atomic chains containing a single Kondo atom, Co, and several nonmagnetic atoms, Cu, were assembled atom by atom on Cu(111) with the tip of a scanning tunneling microscope. The resulting one-dimensional wires, Cu$_m$CoCu$_n$ ($0\leq m, n\leq 5$), exhibit a rich evolution of the single-Co Kondo effect with the variation of $m$ and $n$, as inferred from changes in the line shape of the Abrikosov-Suhl-Kondo resonance. The most striking result is the quenching of the resonance in CuCoCu$_2$ and Cu$_2$CoCu$_2$ clusters. State-of-the-art first-principles calculations were performed to unravel possible microscopic origins of the remarkable experimental observations.