First-principles Calculation of the Single Impurity Surface Kondo Resonance

TL;DR

This paper uses first-principles calculations to analyze the surface and bulk wavefunctions of Cu(111) and their hybridization with Co adatoms, providing insights into the Kondo resonance and tunneling conductance.

Contribution

It offers a detailed first-principles analysis of the hybridization energies and tunneling conductance for Co impurities on Cu(111), highlighting the dominance of bulk states in the Kondo effect.

Findings

Bulk states dominate the Kondo temperature contribution.

Good agreement with experiments at short distances (<6 Å).

Indicates the need for new models at larger distances.

Abstract

We have performed first-principles calculation of the surface and bulk wavefunctions of the Cu(111) surface and their hybridization energies to a Co adatom, including the potential scattering from the Co. By analyzing the calculated hybridization energies, we found the bulk states dominate the contribution to the Kondo temperature, in agreement with recent experiments. Furthermore, we also calculate the tunneling conductance of a scanning tunneling microscope (STM) and compare our results with recent experiments of Co impurities in the Cu(111) surface. Good quantitative agreement is found at short parallel impurity-tip distances (< 6 A). Our results indicate the need for a new formulation of the problem at larger distances.