The Kondo effect of a Co atom on Cu(100) was investigated with a low-temperature scanning tunneling microscope using a monoatomically sharp nickel tip. Upon a tip-Co contact, the differential conductance spectra exhibit a spin-split asymmetric Kondo resonance. The computed ab initio value of the exchange coupling is too small to suppress the Kondo effect, but sufficiently large to produce the splitting observed. A quantitative analysis of the line shape using the numerical renormalization group technique indicates that the junction spin polarization is weak.
@article{arxiv.1609.02363,
title = {Kondo resonance of a Co atom exchange coupled to a ferromagnetic tip},
author = {D. -J. Choi and S. Guissart and M. Ormaza and N. Bachellier and O. Bengone and P. Simon and L. Limot},
journal= {arXiv preprint arXiv:1609.02363},
year = {2016}
}