Magnetic skyrmions are vortex-like topological spin textures often observed to form a triangular-lattice skyrmion crystal in structurally chiral magnets with Dzyaloshinskii-Moriya interaction. Recently β-Mn structure-type Co-Zn-Mn alloys were identified as a new class of chiral magnet to host such skyrmion crystal phases, while β-Mn itself is known as hosting an elemental geometrically frustrated spin liquid. Here we report the intermediate composition system Co7Zn7Mn6 to be a unique host of two disconnected, thermal-equilibrium topological skyrmion phases; one is a conventional skyrmion crystal phase stabilized by thermal fluctuations and restricted to exist just below the magnetic transition temperature Tc, and the other is a novel three-dimensionally disordered skyrmion phase that is stable well below Tc. The stability of this new disordered skyrmion phase is due to a cooperative interplay between the chiral magnetism with Dzyaloshinskii-Moriya interaction and the frustrated magnetism inherent to β-Mn.
@article{arxiv.1811.02337,
title = {Disordered skyrmion phase stabilized by magnetic frustration in a chiral magnet},
author = {K. Karube and J. S. White and D. Morikawa and C. D. Dewhurst and R. Cubitt and A. Kikkawa and X. Z. Yu and Y. Tokunaga and T. Arima and H. M. Rønnow and Y. Tokura and Y. Taguchi},
journal= {arXiv preprint arXiv:1811.02337},
year = {2021}
}