Three-Dimensional Neutron Far-Field Tomography of a Bulk Skyrmion Lattice

Published

August 13, 2023

Author(s)

Melissa Henderson, Benjamin Heacock, Markus Bleuel, David Cory, Colin Heikes, Michael G. Huber, Jeffery Krzywon, Olivier Nahman-Lévesque, Graeme Luke, M Pula, Dusan Sarenac, Kirill Zhernenkov, Dmitry Pushin

Abstract

Magnetic skyrmions are localized non-collinear spin textures, characterized by an integer topo-logical charge. Their nanometric size and topological protection gives rise to unique dynamics and emergent electromagnetic phenomena, ideal for spintronic applications. Skyrmions are thought to nucleate and annihilate along their depth on points of vanishing magnetization, called Bloch points. However, owing to a lack of bulk techniques, experimental visualizations of skyrmion lattices and their stabilization through defects in three-dimensions remain elusive. Here, we present three-dimensional visualizations of a bulk Co8Zn8Mn4 skyrmion lattice through a tomographic algorithm which processes multi-projection small angle neutron scattering measurements to generate mean scattering feature reconstructions (MSFR) of the bulk spin textures. Digital phantoms validated the algorithm; reconstructions of the sample show a disordered skyrmion lattice with a topological saturation of 63 %, exhibiting three-dimensional topological transitions through two different emergent (anti)monopole defect pathways with densities of 147 µm−3 and 21 µm−3 for branching and segmentation events, respectively. These results serve as the first experimentally-informed visualizations of bulk skyrmion lattice structures and defects in three-dimensions, providing novel insights into skyrmion stabilization and topological transition pathways. This technique opens the door to future studies of bulk skyrmion behavior on unprecedented length scales, guiding the development and manipulation of skyrmion materials for spintronic applications.

Citation

ACS Nature, Physics

Volume

106

Issue

9

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevB.106.094435

Local Download

Keywords

neutron, Skyrmion, tomography

Citation

Henderson, M. , Heacock, B. , Bleuel, M. , Cory, D. , Heikes, C. , Huber, M. , Krzywon, J. , Nahman-Lévesque, O. , Luke, G. , Pula, M. , Sarenac, D. , Zhernenkov, K. and Pushin, D. (2023), Three-Dimensional Neutron Far-Field Tomography of a Bulk Skyrmion Lattice, ACS Nature, Physics, [online], https://doi.org/10.1103/PhysRevB.106.094435, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956676 (Accessed January 3, 2025)