Generation of Bloch Points with Controlled Spin Texture Using Geometrical Boundary Conditions
Abstract
Bloch points are three-dimensional topological singularities in magnetization that play a key role in topological transformations of spin textures, such as skyrmion creation or annihilation. While topology often enforces the existence of Bloch points in confined geometries like cylindrical nanowires, deterministic control over their position and magnetic configuration remains challenging. Here we demonstrate the generation of Bloch points with controlled spin texture by engineering geometrical boundary conditions in three-dimensional nanomagnets. By introducing a chirality interface between two three-dimensional double-helix nanowires of opposite handedness, forming a kinked, non-collinear structure, we impose competing topological constraints that uniquely define the magnetization configuration surrounding the Bloch point. A saturating magnetic field nucleates head-to-head or tail-to-tail domain configurations at the chirality interface, producing a Bloch-point domain wall with deterministic polarity, circulation and helicity. This geometrical approach enables full three-dimensional control of Bloch point domain walls allowing deterministic engineering of their spin texture and its selective coupling to current-induced Oersted fields.
Comments: main manuscript: 15 pages and 5 figures; supplement: 12 pages including 7 figures
Cite
@article{arxiv.2605.29672,
title = {Generation of Bloch Points with Controlled Spin Texture Using Geometrical Boundary Conditions},
author = {Naëmi Leo and Daniel Wolf and Alicia Estela Herguedas Alonso and Oleksandr Zaiets and Jakub Jurczyk and Takeaki Gokita and John Fullerton and Dedalo Sanz-Hernandez and Claire Donnelly and Andrea Sorrentino and Eva Pereiro and Lucia Aballe and Peter Fischer and Rachid Belkhou and Claas Abert and Dieter Suess and Axel Lubk and Aurelio Hierro-Rodriguez and Amalio Fernández-Pacheco},
journal= {arXiv preprint arXiv:2605.29672},
year = {2026}
}