- Editors' Suggestion
- Letter
Tilt-driven antiferroelectricity in
Phys. Rev. Materials 7, L071401 – Published 12 July, 2023
DOI: https://doi.org/10.1103/PhysRevMaterials.7.L071401
Abstract
Antiferroelectricity is a state of matter that has so far eluded a clear-cut definition. Even in the best-known material realization, , the physical nature of the driving force towards an antipolar order has not been settled yet. Here, by building a Landau-like continuum Hamiltonian from first principles via an exact long-wave approach, we reconcile the existing theories in terms of a single physical mechanism. In particular, we find that a formerly overlooked trilinear coupling between tilts, tilt gradients, and polarization provides a surprisingly accurate description of the energetics and structure of the antiferroelectric ground state of . We discuss the relevance of our findings to other ferrielectric and incommensurate polar structures that were recently observed in perovskites.