Emergence of topological bimerons in monolayer CrSBr

The rich and fascinating physics of topological spin textures in van der Waals (vdW) two-dimensional magnets has motivated recent growing interests, though a comprehensive understanding remains elusive. Here, in atomistic simulations on monolayer CrSBr, we find two magnetic phases emerging under nonequilibrium conditions at distinct temperatures: a standard ferromagnetic transition Tc and a lower temperature T*. Moreover, the real-space analysis of the spin texture reveals the emergence of metastable topological bimeron defects below T*, showing an algebraic-like decaying spin-spin correlation function. The Dzyaloshinskii-Moriya interaction, induced by the local site asymmetry in the centrosymmetric CrSBr monolayer, is proved to be the origin of the bimeron's formation. Furthermore, the increasing bimeron density upon increasing the cooling rate follows a Kibble-Zurek behavior, suggesting a handle to drive and control topological bimerons below T*. Our results put forward CrSBr as an important candidate for the investigation of the nonequilibrium behavior of bimerons in vdW magnets.