Kondo effect of cobalt adatom on zigzag graphene nanoribbon

TL;DR

This paper investigates the Kondo effect caused by a cobalt adatom on zigzag graphene nanoribbons using ab-initio calculations and various many-body approximation methods to analyze the magnetic and electronic interactions.

Contribution

It provides a detailed theoretical analysis of the Kondo effect in a novel graphene-based system, highlighting the role of orbital and spin interactions.

Findings

Cobalt adatom acts as a spin 1/2 impurity with specific orbital contributions.

Interplay of spin and orbital degrees influences many-body resonances.

Electronic and magnetic structure peculiarities affect the Kondo resonance.

Abstract

Based on ab-initio calculations we discuss Kondo effect due to Co adatom on graphene zigzag nanoribbon. Co atom located at hollow site behaves as spin S = 1/2 impurity with dxz and dyz orbitals contributing to magnetic moment. Dynamical correlations are analyzed with the use of complementary approximations: mean field slave boson approach, noncrossing approximation and equation of motion method. The impact of interplay between spin and orbital degrees of freedom together with the effect of peculiarities of electronic and magnetic structure of nanoribbon on many-body resonances is examined.