Interactions and magnetic moments near vacancies and resonant impurities in graphene

TL;DR

This paper investigates how electronic interactions influence magnetic moments near vacancies and resonant impurities in graphene, revealing the formation of local moments and ferromagnetic coupling through advanced quantum simulations.

Contribution

It introduces a non-perturbative approach combining dynamical mean-field theory and quantum Monte Carlo to study magnetic phenomena in defected graphene.

Findings

Interactions narrow the resonance width.

Local moments form near vacancies and impurities.

Susceptibility indicates ferromagnetic coupling.

Abstract

The effect of electronic interactions in graphene with vacancies or resonant scatterers is investigated. We apply dynamical mean-field theory in combination with quantum Monte Carlo simulations, which allow us to treat non-perturbatively quantum fluctuations beyond Hartree-Fock approximations. The interactions narrow the width of the resonance and induce a Curie magnetic susceptibility, signaling the formation of local moments. The absence of saturation of the susceptibility at low temperatures suggests that the coupling between the local moment and the conduction electrons is ferromagnetic.