Skyrmion lattice with a giant topological Hall effect in a frustrated triangular-lattice magnet

TL;DR

This paper reports the discovery of a Bloch-type skyrmion state in a frustrated centrosymmetric triangular-lattice magnet, evidenced by a giant topological Hall effect and in-plane spin modulation, expanding the understanding of skyrmion formation.

Contribution

It demonstrates the emergence of skyrmions in a centrosymmetric frustrated magnet, a phenomenon previously associated mainly with noncentrosymmetric structures.

Findings

Identification of a field-induced skyrmion phase via topological Hall response

Observation of in-plane spin modulation with resonant x-ray scattering

Skyrmions in centrosymmetric magnets expand potential for spintronic applications

Abstract

Geometrically frustrated magnets provide abundant opportunities for discovering complex spin textures, which sometimes yield unconventional electromagnetic responses in correlated electron systems. It is theoretically predicted that magnetic frustration may also promote a topologically nontrivial spin state, i.e., magnetic skyrmions, which are nanometric spin vortices. Empirically, however, skyrmions are essentially concomitant with noncentrosymmetric lattice structures or interfacial-symmetry-breaking heterostructures. Here, we report the emergence of a Bloch-type skyrmion state in the frustrated centrosymmetric triangular-lattice magnet Gd2PdSi3. We identified the field-induced skyrmion phase via a giant topological Hall response, which is further corroborated by the observation of in-plane spin modulation probed by resonant x-ray scattering. Our results exemplify a new gold mine of magnetic frustration for producing topological spin textures endowed with emergent electrodynamics in centrosymmetric magnets.