Nonequilibrium chiral soliton lattice in the monoaxial chiral magnet MnNb3S6

Abstract

In a magnetic superlattice composed of kinks in a ferromagnetic spin array, the change in the kink number requires the movement of the kinks to and from the crystal surface. Namely, the kinks must have a velocity, and the superlattice must be nonequilibrium. Evidence of the nonequilibrium state has never been observed in previous model compounds. In ${\mathrm{MnNb}}_{3}{\mathrm{S}}_{6}$, a long magnetization relaxation was observed, and the nature of the nonequilibrium state was more pronounced in the kink annihilation process rather than the kink creation process. The annihilation process can be phenomenologically reproduced using the unfrustrated magnetic clusters model. The nonequilibrium state in the annihilation process has a longer relaxation time than that in the nucleation process, since an energy barrier exists only in the latter.