Abstract
We construct ferroelectric superlattices with varying index to study the effect of confinement on topological defects. We observe a thickness-dependent transition from neutral to charged domain walls and the emergence of fractional vortices. In thin layers, the volume fraction of domain walls grows, lowering the symmetry from to before reaching the nonpolar state, analogous to the group-subgroup sequence observed at the high-temperature ferroelectric to paraelectric transition. Our study shows how dimensional confinement stabilizes textures beyond those in bulk ferroelectric systems.
- Received 10 July 2020
- Revised 12 October 2020
- Accepted 18 February 2021
DOI:https://doi.org/10.1103/PhysRevLett.126.157601
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