RKKY interaction of magnetic impurities in Dirac and Weyl semimetals

TL;DR

This paper theoretically investigates how magnetic impurities interact in Dirac and Weyl semimetals, revealing complex spin interactions influenced by their unique electronic structures, with implications for spintronics applications.

Contribution

It provides a detailed theoretical analysis of the RKKY interaction in Dirac and Weyl semimetals, highlighting the effects of internode processes and spin-momentum locking on magnetic interactions.

Findings

Presence of Heisenberg, Ising, and Dzyaloshinsky-Moriya interactions

Potential for ferromagnetism and complex spin textures

Influence of anisotropic nodes on magnetic interactions

Abstract

We theoretically study the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between magnetic impurities in both Dirac and Weyl semimetals (SMs). We find that the internode process, as well as the unique three-dimensional spin-momentum locking, has significant influences on the RKKY interaction, resulting in both a Heisenberg and an Ising term, and an additional Dzyaloshinsky-Moriya term if the inversion symmetry is absent. These interactions can lead to rich spin textures and possible ferromagnetism in Dirac and time-reversal symmetry-invariant Weyl SMs. The effect of anisotropic Dirac and Weyl nodes on the RKKY interaction is also discussed. Our results provide an alternative scheme to engineer topological SMs and shed new light on the application of Dirac and Weyl SMs in spintronics.