Novel three-dimensional topological magnetic domain walls and their dynamics

Session Information

Location: amf. P7 | "Gheorghe Asachi" Technical University of Iași (TUIAȘI)
Day: 3. Wednesday 17
Time: 14:30-14:50
Chairperson: Krisztian Palotas

Presentation Details

Presentation Type: Oral presentation
Title: Novel three-dimensional topological magnetic domain walls and their dynamics
Abstract: Three-dimensional magnetism promotes a rich complexity of magnetization configurations and domain wall types that are chiral and topologically non-trivial. Examples of these domain walls are Bloch point (BP) or vortex-antivortex (VAV) domain walls (DWs) in 3D nanowires with longitudinal magnetization. Even more complex DWs can exist in nanowires with circular magnetisation. For development of 3D nanotechnologies, it is important to understand the possibility to efficiently manipulate these DWs by external stimuli. Here we discuss from theoretical and modelling perspective their dynamics under external field, current and temperature gradient. The first important characteristic is that only the BP DW is a fast object. However, it is characterized by a complex gyrovector that does not allow its straight motion [1], it goes to the nanowire surface and the known topological transformations from one domain wall to the other may occur [1-4]. Secondly, the shape of this DW is dynamically deformed acquiring the conical shape under the application of the field [3] or butterfly-like shape under the action of current and Oersted field [4]. At the same time, large BP DW velocities, more than 10km/s can be achieved under the action of the field due to the jet-propulsion effect [3]. On the other hand, the VAV DWs are stable but very slow objects, rarely exceeding velocities of 10m/s. Their dynamics is quite complex and they experience a rotational and re-coiling effects [5]. 3D domain walls can also be moved by thermal gradients due to entropic torques [6]. However, they are quite stable and large gradients are necessary to initiate the dynamics. The VAV DW requires smaller gradients than the BP DW.
[1]E. Saugar, et al Phys. Rev. Applied 23, 064028 (2025) .
[2]A. Wartelle et al ,. Phys Rev B 99, 24433 (2019).
[3 ] F.Tejo et al., Nanoscale, 16, 10737 (2024).
[4] J.A.Fernánez-Roldán and O.Chubykalo-Fesenko, APL Mater 10, 111101 (2022).
[5] GHR Bittencourt et al J. Appl. Phys.135, 063906 (2024)
[6] E.Saugar et al, Adv. Funct.Mater. (2026), in press.
[7] D.Altbir et al Sci. Rep. 10, 21911 (2020).

Presenter

Prof Oksana Chubykalo-Fesenko
Instituto de Ciencia de Materiales de Madrid | Spain

Authors

1. Chubykalo-Fesenko, Oksana | Instituto de Ciencia de Materiales de Madrid, CSIC, 28049, Madrid, Spain
2. Saugar, Elias | Instituto de Ciencia de Materiales de Madrid, CSIC, 28049, Madrid, Spain
3. Fernández-Roldan, Jose-Angel | nstituto de Ciencia de Materiales de Madrid, CSIC, 28049, Madrid, Spain
4. Moreno, Roberto | nstituto de Ciencia de Materiales de Madrid, CSIC, 28049, Madrid, Spain