RKKY interaction of in nodal-line semimetals

Motivated by recent upsurge in research of three-dimensional topological semimetals (SMs), we theoretically study the RKKY interaction between magnetic impurities in nodal-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 influence on the RKKY interaction, which leads to strong anisotropic oscillation and unique decay features. In the direction perpendicular to nodal-line plane, as usual, there is only one oscillation period related to the Fermi energy. In contrast, in the nodal-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 nodal-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 nodal-line SM ZrSiSe. Our results shed a light for application of magnetically doped nodal-line SMs in spintronics.

Automated summary

Motivated by recent upsurge in research of three-dimensional topological semimetals, this study theoretically investigates the RKKY interaction between magnetic impurities in nodal-line semimetals with and without chirality, and obtains the analytical expressions. The study finds that the unique toroidal Fermi surface in nodal-line semimetals, distinct from the spheroidal Fermi surface in semimetals with point nodes, has a significant influence on the RKKY interaction, leading to strong anisotropic oscillation and unique decay features.