Generalized Theory of Domain-Wall Width in Multisublattice Heisenberg Magnets.

We propose a general expression for the domain-wall width in generic multisublattice Heisenberg magnets with collinear order and uniaxial anisotropy, applicable to ferro-, antiferro-, and ferrimagnetic orders. The result follows from an exact connection between the domain-wall profile and the long-wavelength spin-wave dispersion, yielding a unified framework for describing magnetic textures across distinct ordering types. The predictions show excellent quantitative agreement with large-scale atomistic spin dynamics simulations over a broad range of exchange and anisotropy values and multisublattice spin structures, including three-dimensional rock-salt-type magnets and two-dimensional honeycomb and kagome ferromagnets. Moreover, we establish a general microscopic foundation for the temperature dependence of the domain-wall width. Our approach offers a powerful tool for understanding domain-wall profiles in complex spin systems.