Low-Energy Domain Wall Racetracks With Multiferroic Topologies*

Conventional racetrack memories move information by pushing magnetic domain walls or other spin textures with spin‑polarized currents, but the accompanying Joule heating inflates their energy budget and can hamper scaling. Here we present a voltage‑controlled, magnetoelectric racetrack in which transverse electric fields translate coupled ferroelectric–antiferromagnetic walls along BiFeO₃ nanostrips at room temperature. Because no charge traverses the track, the switching dissipates orders of magnitude less energy than the most efficient spin‑torque devices with more favourable scaling, making the scheme significantly more attractive at the nanoscale. We further uncover topological magnetoelectric vertex and bi-meron textures that arise at the domain walls from the convergence of type‑I and type‑II spin cycloids, where this topology influences stability upon translation. We observe domain wall velocities of several kilometres per second—matching or surpassing the fastest ferrimagnetic and antiferromagnetic racetracks and approaching the acoustic‑phonon limit of BiFeO₃—while preserving these topologies over tens of micrometers. The resulting high velocity, low energy racetrack delivers nanosecond access times without the thermal overhead of current‑driven schemes, charting a path toward dense, ultralow‑power racetrack devices which rely on spin texture translation.