Manipulation of Topological Boundaries within a Magnetic Domain Wall

Bloch points and transverse walls can serve as topological boundaries within a magnetic domain wall. Here, we investigate the stability and dynamics of these topological boundaries for potential spintronic applications. Using micromagnetic simulations, we reveal the coexistence regimes of Bloch points and transverse walls in thin films with perpendicular magnetic anisotropy. An external in-plane field enables reversible transitions between these states through boundary-mediated Bloch point nucleation and annihilation processes. Under spin-transfer torque, transverse walls exhibit transverse drift and deformation. In contrast, Bloch points move strictly along the domain wall without transverse deflection and feature a Walker breakdown threshold an order of magnitude higher than conventional domain walls. Our findings establish a device concept where binary states correspond to in-plane magnetization orientations separated by mobile topological boundaries, offering new opportunities for spintronic architectures.