Nature materials (2025)

Ferroelectric materials are characterized by a parallel arrangement of electric dipoles, but at the nanoscale they can present vortices and other non-trivial topological structures that combine small size and topological protection, rendering them functionally attractive. The driving force for the appearance of vortices in ferroelectrics is the need to minimize the depolarizing fields at interfaces; by making the polarization rotate, depolarization fields vanish. Antiferroelectrics, by contrast, are defined by an antiparallel arrangement of electric dipoles. A priori, therefore, they lack the depolarization fields that drive the appearance of non-trivial topologies in ferroelectrics. At the atomic scale of the dipoles, however, we find that polar discontinuities can still happen, driving the appearance of topological singularities at ferroelastic domain walls.