Emergence of Transverse Dielectric Response in Ferroelectric Dielectric Heterostructures

TL;DR

This paper reveals that in ferroelectric superlattices with vortex structures, applying an electric field induces significant polarization responses orthogonal to the field, enabling reconfigurable dielectric properties.

Contribution

It demonstrates the emergence and tunability of transverse dielectric responses in vortex-structured ferroelectric heterostructures using second-principles simulations.

Findings

Transverse dielectric response approaches half of diagonal susceptibility.

Transverse susceptibilities can be tuned or reversed with electric fields or strain.

Transition to polarization wave state enhances transverse response.

Abstract

We report the emergence of a transverse dielectric response in PbTiO$_{3}$/SrTiO$_{3}$ superlattices hosting polar vortex structures. Using second-principles simulations, we find that an electric field applied along one direction induces significant local polarization responses along orthogonal directions, with magnitudes approaching half that of the diagonal susceptibility components. These off-diagonal responses are strongly dependent on the topology of the vortex structure and can be deterministically tuned or even reversed via homogeneous electric fields or epitaxial strain. Notably, the transverse susceptibilities become comparable to the diagonal components during a field- or strain-induced transition to a polarization wave state. This discovery opens avenues for engineering reconfigurable nanoscale dielectric responses in topologically textured ferroelectric systems.