Biquadratic Interaction Correlated Topological Spin Textures and Dynamics in 2D Ferrimagnet

Abstract 2D ferrimagnets provide fertile ground for emergent spin textures, yet the robustness and controllability remain elusive. Here, the topological spin textures and dynamics in the honeycomb ferrimagnet CrWC ₂ S ₆ are investigated by combining density functional theory with atomistic spin simulations. Bilinear interactions yield only a weak in‐plane magnetic anisotropy, whereas the inclusion of biquadratic exchange, extracted via energy mapping, dramatically reorients it into a strong out‐of‐plane anisotropy. This pronounced change transforms the texture landscape from collective states such as skyrmion lattices and stripe domains to isolated solitons, including skyrmions and domain‐wall skyrmions. Thiele's equation accurately reproduces their transport dynamics in excellent agreement with direct Landau‐Lifshitz‐Gilbert simulations. Specifically, isolated skyrmions exhibit isotropic motion, whereas domain‐wall skyrmions display anisotropic dynamics, with certain angles enabling suppression of the Hall velocity. Parameter modifications further indicate possible emergence of domain‐wall bimerons, bimeron chains, and purely transverse soliton motion. These results identify biquadratic exchange as a hidden design knob for anisotropy engineering and demonstrate its key role in enabling tunable solitonic topological states in 2D ferrimagnets.