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  • Open Access

Topological transition from a hopfion to a toron via flexoelectric self-polarization in chiral liquid crystals

Paul Leask*

  • *Contact author: palea@kth.se
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Phys. Rev. Research 7, 043001 – Published 1 October, 2025

DOI: https://doi.org/10.1103/gy6m-m7ck

Abstract

The presence of topological defects in apolar chiral liquid crystals causes orientational distortions, leading to nonuniform strain. This nonuniform strain generates an electric polarization response due to the flexoelectric effect, which induces an internal electric field. Associated with this electric field is an electrostatic self-energy, which has a backreaction on the director field. Calculation of this internal electric field and its resulting backreaction on the director field is complicated. We propose a method to do such, adapting a method recently developed to study the magnetostatic self-interaction effect on skyrmions in chiral ferromagnets. Bloch skyrmions in chiral magnets are solenoidal and are unaffected by the magnetostatic self-interaction. However, Bloch skyrmions in liquid crystals yield nonsolenoidal flexoelectric polarization and, thus, are affected by the electrostatic self-interaction. Additionally, as the flexoelectric coefficients are increased in strength, a transition from a hopfion to a toron is observed in three-dimensional confined systems.

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Phys. Rev. Research 7, 043001– Published 1 October, 2025
  • Received 28 April 2025
  • Accepted 1 September 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by Bibsam.

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