Spin and orbital transport in magnetic systems going beyond s-wave

Modern electronics has transformed society by controlling the motion of electric charge. Novel spintronic devices can play a role in the quest for GreenIT if they are stable and can transport and manipulate angular momentum with low power. Conventional devices based on ferromagnetism that has an s-wave spin symmetry have been proposed, where switching by energy-efficient approaches is used to manipulate topological spin structures in 2D&3D [1].

We combine the enhanced stability of topological states due to chiral interactions with enhanced manipulation efficiency using novel spin orbit torques [2]. Using the orbital degree of freedom increases the switching efficiency drastically further [3].

Enhanced stability is found going beyond s-wave magnets to systems with compensated magnetic moments that are insensitive to stray fields and also exhibit ultra-fast dynamics. Starting with synthetic antiferromagnets we demonstrate new meron topological spin structures [4] and enhanced topological spin structure dynamics [5].

Particular symmetries enable even in systems with fully compensated magnetic order spin-polarized Fermi surfaces. This includes non-collinear antiferromagnets [6] that can exhibit p-wave spin symmetry as well as collinear d-wave (e.g. RuO2) and g-wave altermagnets (e.g. CrSb) where we reveal the spin-split bands [7]. In the altermagnet hematite that can host antiferromagnetic antiskyrmions we find that ultra-low damping enables long distance spin transport and the altermagnetic nature manifests itself in the crystal Hall effect [8].

2D materials that can exhibit these symmetries are particularly exciting as heterostructures of differently ordered magnetic and non-magnetic materials with atomically flat interfaces lead to enhanced coupling effects [9].

Finally, such systems are not only of interest from a fundamental science point of view but their stability, efficient manipulation and fast dynamics also hold prospects for a range of applications such as memory and unconventional computing [10].

[1] K. Everschor-Sitte et al., Perspective in J. Appl. Phys. 124, 240901 (2018); D. Han et al., Nature Mater. 18, 703 (2019).
[2] S. Woo et al., Nature Mater. 15, 501 (2016); K. Litzius et al., Nature Phys., 13, 170 (2017); Nature Electron. 3, 30 (2020).
[3] S. Ding et al., Phys. Rev. Lett. 125, 177201 (2020); Phys. Rev. Lett. 128, 067201 (2022); R. Gupta et al., Nature Commun. 16, 130 (2025); C. Schmitt et al., Science (2026) (arxiv:2603.06425).
[4] M. Bhukta et al., Nature Commun. 15, 1641 (2024); Nature Phys. (2026) (arxiv :2508.17967).
[5] T. Dohi et al., Nature Commun. 14, 5424 (2023).
[6] A. Rajan et al., Comm. Mater. 7, 73 (2026); A. Bose et al., Nano Lett. 25, 8073 (2025).
[7] O. Fedchenko et al., Sci. Adv. 10, eadj4883 (2024); S. Reimers et al., Nature Commun. 15, 2116 (2024). [8] R. Lebrun et al., Nature 561, 222 (2018); Nature Commun. 11, 6332 (2020); E. Galindez-Ruales et al., Adv. Mater. 37, e05019 (2025).
[9] Z. Chen et al., J. Am. Chem. Soc. 138, 15488 (2016); A. Balan et al., Adv. Mater. 2403685 (2024).
[10] J. Zázvorka et al., Nature Nanotechnol. 14, 658 (2019); K. Raab et al., Nature Commun. 13, 6982 (2022). G. Beneke et al., Nature Commun. 15, 8103 (2024).

Mathias Kläui is professor of physics at Johannes Gutenberg-University Mainz and adjunct professor at the Norwegian University of Science and Technology.
He received his PhD at the University of Cambridge, after which he joined the IBM Research. He was a junior group leader at the University of Konstanz and then became associate professor in a joint appointment between the EPFL and the PSI in Switzerland before moving to Mainz. His research focuses on nanomagnetism and spin dynamics on the nanoscale in new materials.
His research covers from blue sky fundamental science to applied projects with major industrial partners. He has published more than 430 articles and given more than 250 invited talks.
He is a Fellow of the IEEE, IOP, APS, the European Academy of Sciences and the German National Academy of Science and Engineering and has been awarded a number of prizes and
scholarships.
He has been one of the 2020/2021 IEEE Magnetics Society Distinguished Lecturers.
Contact details and more information at www.klaeui-lab.de.

Mathias will be at MPSD 1,5 days on Monday (3.08.2026) and Tuesday (4.06. 2026). To schedule a meeting, please feel free to contact Alexandra Kather.