Fermi Surface Nesting Driving the RKKY Interaction in the Centrosymmetric Skyrmion Magnet Gd2PdSi3

TL;DR

This study combines ARPES, DFT, and scattering data to reveal that Fermi surface nesting drives the RKKY interaction, which in turn stabilizes magnetic skyrmions in Gd2PdSi3, a centrosymmetric skyrmion magnet.

Contribution

It demonstrates the direct link between Fermi surface nesting and skyrmion formation via RKKY interaction in Gd2PdSi3, supported by combined experimental and theoretical analysis.

Findings

Fermi surface nesting matches magnetic order wavevector.

ARPES and DFT show consistent electronic structure.

RKKY interaction explains skyrmion stability.

Abstract

The magnetic skyrmions generated in a centrosymmetric crystal were recently first discovered in Gd2PdSi3. In light of this, we observe the electronic structure by angle-resolved photoemission spectroscopy (ARPES) and unveil its direct relationship with the magnetism in this compound. The Fermi surface and band dispersions are demonstrated to have a good agreement with the density functional theory (DFT) calculations carried out with careful consideration of the crystal superstructure. Most importantly, we find that the three-dimensional Fermi surface has extended nesting which matches well the q-vector of the magnetic order detected by recent scattering measurements. The consistency we find among ARPES, DFT, and the scattering measurements suggests the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction involving itinerant electrons to be the formation mechanism of skyrmions in Gd2PdSi3.