Transient Antiskyrmion-Mediated Topological Transitions in Isotropic Magnets

From elementary particles to cosmological structures, topological solitons are ubiquitous nonlinear excitations valued for their robustness and complex interactions. In magnetism, solitons such as skyrmions and antiskyrmions behave analogously to particles and antiparticles, typically annihilating in pairs in accordance with topological conservation laws. Here the stripe-to-skyrmion transition is experimentally observed and a model for a skyrmion-antiskyrmion-skyrmion intertwined state is introduced, in which the central antiskyrmion is annihilated, leading to an increase in the local topological number. Because this transition occurs repeatedly across the film, the cumulative effect produces a global increase in the total topological charge. This model reflects a breakdown of topological protection in isotropic Dzyaloshinskii-Moriya interaction (DMI) materials, where symmetry constraints render the antiskyrmion energetically unstable and thermally activated. Using micromagnetic simulations and minimum-energy-path calculations, the antiskyrmion is identified as a transient, metastable excitation. To highlight its functional potential, this stripe-to-skyrmion transition within a Hall device is exploited to generate stochastic bitstreams, which are subsequently used in a proof-of-concept probabilistic computing demonstration. These results contribute to the understanding of topological spin-texture dynamics and suggest opportunities for leveraging their transient behavior in probabilistic computing architectures.