Topology of the polarization field in ferroelectric nanowires from first principles

TL;DR

This paper investigates the complex polarization field topologies in ferroelectric barium titanate nanowires using first-principles calculations, revealing novel topological defects influenced by surface effects.

Contribution

It introduces the first-principles analysis of topological defects with various winding numbers in ferroelectric nanowires, expanding understanding of their polarization textures.

Findings

Identification of topological defects with different winding numbers

Polarization field orientation varies near defects

Surface effects influence polarization accommodation

Abstract

The behaviour of the cross-sectional polarization field is explored for thin nanowires of barium titanate from first-principles calculations. Topological defects of different winding numbers have been obtained, beyond the known textures in ferroelectric nanostructures. They result from the inward accommodation of the polarization patterns imposed at the surface of the wire by surface and edge effects. Close to a topological defect the polarization field orients out of the basal plane in some cases, maintaining a close to constant magnitude, whereas it virtually vanishes in other cases.