Controlled motion of polar vortex boundary in oxide heterostructures

Polar vortices in ferroelectric heterostructures hold promise for high-density, energy-efficient nanoelectronics, but their controlled motion remains elusive due to strong pinning and lattice-coupled dynamics. Here, we report real-time observation of vortex boundary motion in PbTiO₃/SrTiO₃ heterostructures using localized trailing electric fields applied via a conductive atomic force microscopy (AFM) tip. The vortex boundaries show reversible motion that depends on both field polarity and AFM tip trajectory. By precisely steering the tip along specific paths, we achieve controlled, reconfigurable vortex boundary motion with remarkable stability over extended periods. In-situ scanning transmission electron microscopy further confirmed the controlled motion of the vortex boundary. Phase-field simulations reveal that this motion is governed by switching of the zigzag pattern at the vortex core, pinpointing the underlying physical mechanism. These results establish the feasibility of externally controlled vortex boundary motion, advancing both fundamental understanding of polar topological dynamics and prospects for next-generation polar-vortex-based nanoelectronic devices.