RKKY interaction between adsorbed magnetic impurities in graphene: symmetry and strain effects

TL;DR

This paper investigates how symmetry and strain influence the RKKY magnetic interaction between impurities in graphene, revealing ways to control magnetic coupling through lattice symmetry and strain engineering.

Contribution

It demonstrates that symmetry considerations and uniaxial strain significantly affect the decay and sign of the RKKY interaction in graphene, offering new control mechanisms.

Findings

Symmetry inclusion clarifies the decay and oscillation features of RKKY in graphene.

Uniaxial strain modifies the decay rate and range of magnetic interactions.

Strain engineering can be used to manipulate magnetic interactions in graphene.

Abstract

The growing interest in carbon-based spintronics has stimulated a number of recent theoretical studies on the RKKY interaction in graphene, with the aim of determining the most energetically favourable alignments between embedded magnetic moments. The RKKY interaction in undoped graphene decays faster than expected for conventional two-dimensional materials and recent studies suggest that the adsorption configurations favoured by many transition-metal impurities may lead to even shorter ranged decays and possible sign-changing oscillations. Here we show that these features emerge in a mathematically transparent manner when the symmetry of the configurations is included in the calculation. Furthermore, we show that by breaking the symmetry of the graphene lattice, via uniaxial strain, the decay rate, and hence the range, of the RKKY interaction can be significantly altered. Our results suggest that magnetic interactions between adsorbed impurities in graphene can be manipulated by careful strain engineering of such systems.