Exchange interaction of magnetic impurities in graphene

TL;DR

This paper theoretically investigates the indirect exchange interaction between magnetic impurities in graphene, considering spin-orbit effects, revealing an exponential decay of interaction and sublattice dependence, which challenges the traditional RKKY model.

Contribution

It introduces a modified model for exchange interaction in graphene accounting for spin-orbit induced energy gaps, differing from the standard RKKY approach.

Findings

Interaction decays exponentially with distance

Dependence on sublattice configuration

Energy gap affects interaction range

Abstract

The indirect exchange interaction between magnetic impurities localized in a graphene plane is considered theoretically, with the influence of intrinsic spin-orbit interaction taken into account. Such an interaction gives rise to an energy gap at the Fermi level, which makes the usual RKKY model not applicable. The results show that the effective indirect exchange interaction is described by a range function which decays exponentially with the distance between magnetic moments. The interaction is also shown to depend on whether the two localized moments belong to the same sublattice or are located in two different sublattices.