Relevance of complete Coulomb interaction matrix for the Kondo problem: Co impurity on Cu(111)

TL;DR

This paper demonstrates that including the full Coulomb interaction matrix is crucial for accurately modeling the Kondo effect in a Co impurity on Cu(111), advancing first-principles calculations of Kondo phenomena.

Contribution

It introduces a method using continuous-time QMC with a complete Coulomb matrix to improve Kondo system simulations, highlighting limitations of truncated models.

Findings

Full Coulomb matrix significantly affects Kondo resonance calculations

Standard truncated models can be quantitatively inaccurate

First-principles approach enables better Kondo temperature predictions

Abstract

The electronic structure of a prototype Kondo system, a cobalt impurity in a copper host is calculated with accurate taking into account of correlation effects on the Co atom. Using the recently developed continuous-time QMC technique, it is possible to describe the Kondo resonance with a complete four-index Coulomb interaction matrix. This opens a way for completely first-principle calculations of the Kondo temperature. We have demonstrated that a standard practice of using a truncated Hubbard Hamiltonian to consider the Kondo physics can be quantitatively inadequate.