Altermagnetism: a discovery that could transform electronics
Publication : Badura, W. H. Campos, V. K. Bharadwaj, I. Kounta, L. Michez, M. Petit, J. Rial, M. Leiviskä, V. Baltz, F. Krizek, D. Kriegner, J. Zeleny, J. Zemen, S. Telkamp, S. Sailler, M. Lammel, R. J. Ubiergo, A. Birk Hellenes, R. Gonzalez-Hernandez, J. Sinova, T. Jungwirth, S. T. B. Goennenwein, L. Smejkal, H. Reichlova
Observation of the anomalous Nernst effect in altermagnetic candidate Mn5Si3
Nature Communications 16, 7111 (2025)
DOI : 10.1038/s41467-025-62331-7
The digital revolution, a driving force behind societal and economic transformation, now depends on ever more powerful and energy-efficient electronics. In this context, the discovery of altermagnetic materials represents a remarkable breakthrough for spintronics—a field of electronics recognized in the French national strategy as one of the key solutions for developing more frugal and agile digital technologies. These disruptive materials combine the assets of ferromagnets—their ability to spin-polarize electrical currents—and antiferromagnets—their robustness against magnetic fields and ultrafast dynamics in the terahertz range. This breakthrough paves the way for spintronic devices that are faster, denser, and more sustainable.
Among the hundreds of predicted altermagnetic compounds, only four have been experimentally confirmed to date. Mn₅Si₃ stands out due to its composition of abundant, low-cost elements with weak spin-orbit coupling, allowing its spin-split bands to be attributed to purely non-relativistic effects arising from the arrangement of its magnetic moments relative to its crystalline symmetries. As part of a Franco-German-Czech collaboration, the SPIXY team at CINaM has uncovered several key signatures of altermagnetism in epitaxial thin films of Mn₅Si₃: a validated theory, a strong anomalous Hall effect in the absence of magnetization or external magnetic fields, and a pronounced anisotropy of this effect directly linked to the material crystallinity. In this new publication, we report—for the first time in an altermagnetic material—the spontaneous presence of the anomalous Nernst effect. This work demonstrates the potential of an altermagnetic material composed of light, non-toxic elements for applications in thermoelectrics and spin-caloritronics. It also fills a long-standing gap by revealing the spontaneous anomalous Nernst effect in collinear compensated magnets, thereby opening new avenues for sustainable and high-performance spintronics.
