RKKY interaction of magnetic impurities in node-line semimetals

TL;DR

This paper provides an analytical study of the RKKY interaction between magnetic impurities in node-line semimetals, revealing unique oscillation and decay behaviors influenced by their toroidal Fermi surface, with implications for spintronics.

Contribution

The study derives analytical expressions for RKKY interactions in node-line semimetals, highlighting their unique anisotropic oscillations and decay features due to the toroidal Fermi surface.

Findings

RKKY interaction exhibits strong anisotropic oscillations.

Distinct beating pattern in the plane of the node-line.

Decay rate shows two-dimensional characteristics.

Abstract

Motivated by the recent upsurge in research of three-dimensional topological semimetals (SMs), we theoretically study the RKKY interaction between magnetic impurities in node-line SMs with and without the chirality and obtain the analytical expressions. We find that unique toroidal Fermi surface (FS) in nodal-line SMs, distinctly different from the spheroid FS in the SMs with the point nodes, has significant influences on the RKKY interaction, leading to strong anisotropic oscillation and unique decay features. In the direction perpendicular to node-line plane, as usual, there is only one oscillation period related to the Fermi energy. In contrast, in the node-line plane, the RKKY interaction form a beating pattern and oscillates more rapidly with two distinct periods: one is coming from the Fermi energy and the other is from the radius of node-line. More importantly, inside nodal-line SMs bulk, the decay rate of RKKY interaction manifests a typical two-dimensional feature for impurities aligned along the direction perpendicular to nodal-line plane. Furthermore, the magnetic interactions in nodal-line SMs with linear and quadratic dispersions in the nodal-line plane are compared. We also discuss the possible application of the present theory on realistic NLSM ZrSiSe. Our results shed the light for application of magnetically doped node-line SMs in spintronics.