Multiple-q noncollinear magnetism in an itinerant hexagonal magnet

R. Takagi, J. S. White, S. Hayami, R. Arita, D. Honecker, H. M. Rønnow, Y. Tokura, S. Seki
2018 Science Advances  
Multiple-q spin order, i.e., a spin texture characterized by a multiple number of coexisting magnetic modulation vectors q, has recently attracted attention as a source of nontrivial magnetic topology and associated emergent phenomena. One typical example is the triple-q skyrmion lattice state stabilized by Dzyaloshinskii-Moriya interactions in noncentrosymmetric magnets, while the emergence of various multiple-q states of different origins is expected according to the latest theories. Here, we
more » ... theories. Here, we investigated the magnetic structure of the itinerant polar hexagonal magnet Y3Co8Sn4, in which several distinctive mechanisms favoring multiple-q states are allowed to become active. Small-angle neutron-scattering experiments suggest the formation of incommensurate triple-q magnetic order with an in-plane vortex-like spin texture, which can be most consistently explained in terms of the novel four-spin interaction mechanism inherent to itinerant magnets. The present results suggest a new route to realizing exotic multiple-q orders and that itinerant hexagonal magnets, including the R3M8Sn4 family with wide chemical tunability, can be a unique material platform to explore their rich phase diagrams.
doi:10.1126/sciadv.aau3402 fatcat:bwgj5ebrzvbuxan3wwkqyrwnom