  We introduce antiferroelectric topological insulators as a new class of
functional materials in which an electric field can be used to control
topological order and induce topological phase transitions. Using first
principles methods, we predict that several alkali-MgBi orthorhombic members of
an $ABC$ family of compounds are antiferroelectric topological insulators. We
also show that epitaxial strain and hydrostatic pressure can be used to tune
the topological order and the band gap of these $ABC$ compounds.
Antiferroelectric topological insulators could enable precise control of
topology using electric fields, enhancing the applicability of topological
materials in electronics and spintronics.
