The zero-bias anomaly in conductance spectra of single Co atoms on Cu(111) observed at ≈ 4 K, which has been interpreted as being due to a Kondo resonance, is strongly modified when the Co atoms are attached to monatomic Cu chains. Scanning tunneling spectra measured at 340 mK in magnetic fields exhibit all characteristics of spin-flip excitations. Their dependence on the magnetic field reveals a magnetic anisotropy and suggests a non-collinear spin state. This indicates that spin-orbit coupling (SOC), which has so far been neglected in theoretical studies of Co/Cu(111), has to be taken into account. According to our density functional theory and multi-orbital quantum Monte Carlo calculations SOC suppresses the Kondo effect for all studied geometries.
@article{arxiv.2303.03317,
title = {Spin excitation of Co atoms at monatomic Cu chains},
author = {Neda Noei and Roberto Mozara and Ana M. Montero and Sascha Brinker and Niklas Ide and Filipe S. M. Guimarães and Alexander I. Lichtenstein and Richard Berndt and Samir Lounis and Alexander Weismann},
journal= {arXiv preprint arXiv:2303.03317},
year = {2023}
}