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Abstract 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. 

The electric field manipulates the spin chirality and skyrmion motion direction in a magnetic heterostructure. 

Abstract Terahertz (THz) spin dynamics and vanishing stray field make antiferromagnetic (AFM) materials the most promising candidate for the next-generation magnetic memory technology with revolutionary storage density and writing speed. However, owing to the extremely large exchange energy barriers, energy-efficient manipulation has been a fundamental challenge in AFM systems. Here, we report an electrical writing of antiferromagnetic orders through a record-low current density on the order of 10 6 A cm −2 facilitated by the unique AFM-ferromagnetic (FM) phase transition in FeRh. By introducing a transient FM state via current-induced Joule heating, the spin-orbit torque can switch the AFM order parameter by 90° with a reduced writing current density similar to ordinary FM materials. This mechanism is further verified by measuring the temperature and magnetic bias field dependences, where the X-ray magnetic linear dichroism (XMLD) results confirm the AFM switching besides the electrical transport measurement. Our findings demonstrate the exciting possibility of writing operations in AFM-based devices with a lower current density, opening a new pathway towards pure AFM memory applications. 

Topological insulator (TI) based heterostructure is a prospective candidate for ultrahigh spin-to-charge conversion efficiency due to its unique surface states. We investigate the spin-to-charge conversion in (Bi,Sb)2Te3 (BST)/CoFeB, BST/Ru/CoFeB, and BST/Ti/CoFeB by spin pumping measurement. We find that the inverse Edelstein effect length (λIEE) increases by 60% with a Ru insertion while remains constant with a Ti insertion. This can be potentially explained by the protection of BST surface states due to the high electronegativity of Ru. Such enhancement is independent of the insertion layer thickness once the thickness of Ru is larger than 0.5 nm, and this result suggests that λIEE is very sensitive to the TI interface. In addition, an effectively perpendicular magnetic anisotropy field and additional magnetic damping are observed in the BST/CoFeB sample, which comes from the interfacial spin–orbit coupling between the BST and the CoFeB. Our work provides a method to enhance λIEE and is useful for the understanding of charge-to-spin conversion in TI-based systems.