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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 [1], i.e., magnetic skyrmions. Empirically, however, skyrmions are essentially concomitant with noncentrosymmetric lattice structures or interfacial symmetry-breaking heterostructures [2]. Here, we report the emergence of a Bloch-type skyrmion state in a frustrated centrosymmetric triangular-lattice magnet Gd₂PdSi₃ [3]. 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 platform of magnetic frustration for producing topological spin textures endowed with emergent electrodynamics in centrosymmetric magnets.
[1] C. D. Batista et al., Rep. Prog. Phys. 79, 084504 (2016).
[2] A. Fert et al., Nat. Nanotech. 8, 152 (2013).
[3] T. Kurumaji et al., arXiv:1805.10719.