Switchable Skyrmion-Antiskyrmion Tubes in Rhombohedral BaTiO$_\mathrm{3}$ and Related Materials

TL;DR

This paper demonstrates the stabilization and reversible switching of skyrmion and antiskyrmion tubes in rhombohedral BaTiO$_3$ and related materials using density functional theory, revealing their potential for nanoelectronic applications.

Contribution

It introduces a method to stabilize and switch topological skyrmion structures in ferroelectric materials, overcoming previous energetic barriers and expanding their possible material realizations.

Findings

Skyrmion and antiskyrmion tubes are stabilized in BaTiO$_3$.

Reversible switching of these structures is achieved with electric fields.

The structures are also found in related ferroelectric materials.

Abstract

Skyrmions are stable topological textures that have garnered substantial attention within the ferroelectric community for their exotic functional properties. While previous studies have questioned the feasibility of [001]$_{\text{pc}}$ skyrmion tubes in rhombohedral BaTiO$_3$ due to the high energy cost of 180$^\circ$ domain walls, we demonstrate here their stabilization with topological charges of $\mathcal{Q} = \pm 1$ from density functional theory and second-principles calculations. By enabling extensive vortex and antivortex polarization configurations, the expected prohibitive energetic barriers are overcomed while preserving the topological nature of the structures. Notably, we extend these findings to demonstrate the appearance of skyrmion and antiskyrmion tubes in other related materials, highlighting their broader relevance. Furthermore, our computational experiments indicate that these structures can be directly stabilized and reversibly switched by applied electric fields, establishing a straightforward route for their practical realization and functional control in nanoelectronic devices.