Polar topological structures in perovskites offer promising routes toward next-generation nonvolatile memory and logic devices, yet thermally stable, lead-free, and electrically controllable systems remain rare. Here, by applying machine-learning interatomic potentials and high-throughput screening of over 1300 candidate compounds, we report the emergence of an in-plane polar vortex-antivortex state in ${\mathrm{BiAlO}}_3/{\mathrm{BiGaO}}_3$ superlattices, where each constituent is collinearly (anti)polarized. The vortex topology is found to be stabilized by cooperative coupling between polarization and octahedral rotations. This vortex phase remains the stable ground state up to 900 K and exhibits enhanced stability against deforming electric fields than the typical ${\mathrm{PbTiO}}_3/{\mathrm{SrTiO}}_3$ system. Global electric fields reversibly switch the system between the vortex state and a ferroelectric state. Localized biases write and erase stable nanoscale vortex bits with nonvolatile retention and clear spatial addressability. The presently discovered platform provides a promising route toward advanced storage devices.

Close

PrevNext

View figure in article

• Ferroelectric phase transition
• Ferroelectricity
• Polarization vortices
• Topological phase transition
• Ferroelectrics
• Superlattices
• First-principles calculations
• Machine learning
• Molecular dynamics