Kondo resonance from vacancies in graphene

TL;DR

This paper investigates the formation and characteristics of Kondo resonance in graphene with vacancies using slave-rotor mean-field theory, revealing unique behaviors at the Dirac point and upon doping.

Contribution

It introduces a theoretical analysis of vacancy-induced Kondo resonance in graphene, highlighting critical hybridization thresholds and distinct spectral line-shapes.

Findings

Kondo resonance appears beyond a critical hybridization strength at the Dirac point.

Kondo peak line-shapes differ from Lorentzian profiles typical in metals.

Kondo temperature depends linearly on hybridization, contrasting with quadratic dependence in metals.

Abstract

Using the slave-rotor mean-field theory, we study the formation of Kondo resonance in graphene induced from vacancies. At the Dirac neutrality point, we find acritical hybridization strength beyond which the Kondo resonance takes place, despite vanishing density of states. We also find that the line-shapes of the Kondo peak are entirely different from Lorentzian shown in normal metallic hosts. The dependence of Kondo temperature on the effective hybridization parameter of the spinon field turns out to be linear in contrast to the quadratic dependence in normal metals. Upon doping we find strong electron-hole asymmetry for the dependence of Kondo temperature on the chemical potential.