Complex topologically nontrivial domain walls will most probably play the role of information carriers in three-dimensional magnetic nanostructures. Thus, understanding their dynamics will be crucial for their future applications. We investigate the Bloch-point domain wall stability and dynamics in cylindrical magnetic nanowires within analytical and numerical micromagnetic approaches. Our analysis demonstrates that the Bloch-point magnetization configuration is characterized by inhomogeneous helicity, nontrivial topology, and the nonzero gyrotropic vector. We show that the three-dimensional (3D) Bloch-point gyrovector is different from that for two-dimensional topological solitons, such as magnetic vortices and skyrmions. We analyze the Bloch-point domain wall velocity within the Thiele approach and demonstrate the absence of the Walker breakdown phenomenon. Under applied magnetic field parallel to the nanowire axis, no stationary regime for its dynamics exists, except a limiting case of the infinitely long nanowires. In finite-length nanowires the Bloch-point domain wall experiences a complex oscillatory hyperbolic trajectory, which may lead to its escape through the nanowire side surface. An analytical model of the domain wall is corroborated by micromagnetic modeling demonstrating the Bloch-point nonzero helicity and presenting its dynamical stability diagram. Numerical results are in agreement with the analytically predicted domain wall dynamics based on a 3D gyrovector and confirm the Bloch-point topological Hall effect similar to that found for the magnetic skymion motion. Our results are useful for engineering magnetic response of three-dimensional magnetic textures in future compact nanotechnologies.

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• Domain walls
• Magnetic texture
• Magnetization dynamics
• Micromagnetism
• Skyrmions
• Spin dynamics
• Spintronics
• Symmetry protected topological states