Fermi-Surface Origin of Skyrmion Lattices in Centrosymmetric Rare-Earth Intermetallics

We show from first principles that barrel-shaped structures within the Fermi surface of the centrosymmetric intermetallic compounds GdRu2Si2 and Gd2PdSi3 give rise to Fermi surface nesting, which determines the strength and sign of quasi-two-dimensional Ruderman-Kittel-Kasuya-Yosida pairwise exchange interactions between the Gd moments. This is the principal mechanism leading to their helical single-q spin-spiral ground states, providing transition temperatures and magnetic periods in good agreement with experiment. Using atomistic spin-dynamic simulations, we draw a direct line between the subtleties of the three-dimensional Fermi surface topology and the stabilization of a square skyrmion lattice in GdRu2Si2 at applied magnetic fields as observed in experiment.

Automated summary

We investigate the correlation between Fermi surface structure and spin spiral ground state in intermetallic compounds GdRu2Si2 and Gd2PdSi3 using first principles and spin dynamic simulations, providing a mechanism explanation for the observed transition temperatures and magnetic periods in experiments.