Phys. Rev. Lett. 130, 216801 (2023)

We show that translational boundaries (aka “antiphase boundaries”) in antiferroelectric PbZrO3 can have an arbitrary thickness, becoming de facto domains of a polar ferrielectric phase, with two dipoles in one direction and one in the opposite, embedded within the antiferroelectric matrix. The dual nature of these structures, which are both a domain and a domain wall, makes them very robust (topologically protected) against depolarization. They are strictly an antiferroelectric topological soliton, the thinnest polar structures being only 3 unit-cells in thickness.