RKKY interaction of magnetic impurities in multi-Weyl semimetals

We have systematically investigated the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic impurities in Weyl semimetals with arbitrary monopole charge $Q$. We find that the RKKY interaction becomes intrinsically anisotropic for $Q\ge 2$, and its dependence on Fermi energy and impurity separation is directly controlled by the monopole charge. With the increase of $Q$, the RKKY interaction becomes more long-ranged and more anisotropic, which makes interesting magnetic orders easier to form and thus may have important applications in spintronics.