Magnetic Impurities in Graphene

TL;DR

This study employs quantum Monte Carlo simulations to investigate magnetic impurities in graphene, revealing tunable magnetic moments, unique spectral density behavior, and suppressed correlations, aligning with established theoretical methods.

Contribution

It introduces a detailed quantum Monte Carlo analysis of magnetic impurities in graphene, highlighting the effects of chemical potential tuning on magnetic and electronic properties.

Findings

Magnetic moments can be switched by tuning chemical potential.

Impurity spectral density differs from that in normal metals.

Charge and spin correlations are strongly suppressed.

Abstract

We used a quantum Monte Carlo method to study the magnetic impurity adatoms on graphene. We found that by tuning the chemical potential we could switch the values of the impurity's local magnet moment between relatively large and small values. Our computations of the impurity's spectral density found its behavior to differ significantly from that of an impurity in a normal metal and our computations of the charge-charge and spin-spin correlations between the impurity and the conduction band electrons found them to be strongly suppressed. In general our results are consistent with those from poor man's scaling and numerical renormalization group methods.