Pseudogap and Fermi arc induced by Fermi surface nesting in a centrosymmetric skyrmion magnet

TL;DR

This study uncovers how Fermi surface nesting and RKKY interactions in a centrosymmetric skyrmion magnet lead to pseudogap formation and Fermi arcs, advancing understanding of skyrmion mechanisms in centrosymmetric materials.

Contribution

It reveals the electronic structure and Fermi surface nesting in GdRu2Si2, linking RKKY interactions to skyrmion formation in centrosymmetric magnets.

Findings

Fermi surface nesting consistent with magnetic modulation q-vector

Pseudogap opens at nested Fermi surface regions

Fermi arcs form with twofold symmetry

Abstract

Skyrmions in noncentrosymmetric materials are believed to occur due to the Dzyaloshinskii-Moriya interaction. By contrast, the skyrmion formation mechanism in centrosymmetric materials remains elusive. Here, we reveal the intrinsic electronic structure of the centrosymmetric GdRu2Si2 by selectively measuring magnetic domains using angle-resolved photoemission spectroscopy (ARPES). We found robust Fermi surface (FS) nesting, consistent with the magnetic modulation q-vector detected by the previous resonant x-ray scattering measurements. The pseudogap opens at the nested FS portions, which vary for different magnetic domains. The anomalous pseudogap disconnects the FS to generate Fermi arcs with twofold symmetry. These results indicate that the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction plays a decisive role in generating the screw spin modulation responsible for the skyrmion formation in GdRu2Si2. Furthermore, we demonstrate the flexible nature of magnetism in GdRu2Si2 by manipulating magnetic domains with magnetic field and temperature cyclings, providing potential future applications for data storage and processing devices.