Dipole chains of Bloch point singularities revealed by X-ray magnetic tomography
Abstract
Bloch point singularities play an important role in magnetic systems, mediating changes in topology in three dimensional configurations. However, until now they have only been observed as isolated objects or as part of individual topological textures. Here we present the experimental observation of a 1D dipole chain of Bloch points in an anisotropic chiral magnet using soft X-ray magnetic vector tomography. We identify that the chain of Bloch point singularities lies along a boundary between regions of opposite chirality and that neighbouring Bloch and anti-Bloch points are stable at separations down to 60 nm. The stability of the Bloch points is determined to be closely related to the surrounding topology of the magnetisation configuration and a threshold separation for the spontaneous annihilation of Bloch point-anti-Bloch point pairs within chiral domain walls is identified to be approximately 90 nm in distance. This observation of a chain of Bloch points and the insight into their stability, offers a route to explore the correlative behaviour of such topological point defects. The behaviour and control of such point defects is of relevance for the control of 3D magnetisation configurations, and provides a new route towards the creation of correlated configurations of singularities in a magnetic system.
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BibTeX
@misc{neethirajan2026dipole,
title = {{Dipole chains of Bloch point singularities revealed by X-ray magnetic tomography}},
author = {Jeffrey Neethirajan and Rikako Yamamoto and Marisel Di Pietro Martínez and Luke A. Turnbull and Praveen Vir and Chandra Shekar and Claudia Felser and Luis Carlos Colocho Hurtarte and Benedikt J. Daurer and Majid Kazemian and Burkhard Kaulich and Claire Donnelly},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.31952},
eprint = {2610.31952},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.31952},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Dipole chains of Bloch point singularities revealed by X-ray magnetic tomography
AU - Jeffrey Neethirajan
AU - Rikako Yamamoto
AU - Marisel Di Pietro Martínez
AU - Luke A. Turnbull
AU - Praveen Vir
AU - Chandra Shekar
AU - Claudia Felser
AU - Luis Carlos Colocho Hurtarte
AU - Benedikt J. Daurer
AU - Majid Kazemian
AU - Burkhard Kaulich
AU - Claire Donnelly
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2610.31952
UR - https://arxiv.org/abs/2610.31952
AB - Bloch point singularities play an important role in magnetic systems, mediating changes in topology in three dimensional configurations. However, until now they have only been observed as isolated objects or as part of individual topological textures. Here we present the experimental observation of a 1D dipole chain of Bloch points in an anisotropic chiral magnet using soft X-ray magnetic vector tomography. We identify that the chain of Bloch point singularities lies along a boundary between regions of opposite chirality and that neighbouring Bloch and anti-Bloch points are stable at separations down to 60 nm. The stability of the Bloch points is determined to be closely related to the surrounding topology of the magnetisation configuration and a threshold separation for the spontaneous annihilation of Bloch point-anti-Bloch point pairs within chiral domain walls is identified to be approximately 90 nm in distance. This observation of a chain of Bloch points and the insight into their stability, offers a route to explore the correlative behaviour of such topological point defects. The behaviour and control of such point defects is of relevance for the control of 3D magnetisation configurations, and provides a new route towards the creation of correlated configurations of singularities in a magnetic system.
ER -