We report an excellent realization of the highly non-classical incommensurate spin-density wave (SDW) state in the quantum frustrated antiferromagnetic insulator Cs2CoBr4. In contrast to the well-known Ising spin chain case, here the SDW is stabilized by virtue of competing planar in-chain anisotropies and frustrated interchain exchange. Adjacent to the SDW phase is a broad m=1/3 magnetization plateau that can be seen as a commensurate locking of the SDW state into the up-up-down (UUD) spin structure. This represents the first example of long-sought SDW-UUD transition in triangular-type quantum magnets.
@article{arxiv.2204.10682,
title = {Spin Density Wave versus Fractional Magnetization Plateau in a Triangular Antiferromagnet},
author = {L. Facheris and K. Yu. Povarov and S. D. Nabi and D. G. Mazzone and J. Lass and B. Roessli and E. Ressouche and Z. Yan and S. Gvasaliya and A. Zheludev},
journal= {arXiv preprint arXiv:2204.10682},
year = {2022}
}