Anomalous temperature dependence of local magnetic fields in altermagnetic MnTe

Thomas J. Hicken; Oliver Amin; Alfred Dal Din; J. Hugo Dil; Dominik Kriegner; Hubertus Luetkens; Helena Reichlová; Zaher Salman; Klára Uhlířová; Peter Wadley; Juraj Krempaský; Jonas A. Krieger

arXiv · 2507.14710

Anomalous temperature dependence of local magnetic fields in altermagnetic MnTe

Thomas J. Hicken·Oliver Amin·Alfred Dal Din·J. Hugo Dil·Dominik Kriegner·Hubertus Luetkens·Helena Reichlová·Zaher Salman·Klára Uhlířová·Peter Wadley·Juraj Krempaský·Jonas A. Krieger

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Abstract

Altermagnets are a novel type of magnetic system that has a spin-polarised electric band structure in the absence of a net magnetic moment, leading to exciting prospects in potential device applications. Hexagonal MnTe, a prototypical altermagnet, has arguably shown the most properties consistent with theoretical predictions, including an anomalous Hall effect despite no net magnetisation, and strong altermagnet-induced spin splitting in the electronic band structure. Here we present muon-spin spectroscopy measurements of a single crystal of MnTe. Below room temperature we observe pronounced anomalies in the muon-spin depolarisation, as well as the onset of a second, non-proportional internal field in the absence of an applied field. These findings point to a change in the magnetic structure around $T\simeq250$ K, which coincides with other changes in reported properties, such as transport.

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Thomas J. Hicken, Oliver Amin, Alfred Dal Din, J. Hugo Dil, Dominik Kriegner, Hubertus Luetkens, Helena Reichlová, Zaher Salman, Klára Uhlířová, Peter Wadley, Juraj Krempaský, Jonas A. Krieger. 2025-07-19. Anomalous temperature dependence of local magnetic fields in altermagnetic MnTe. https://arxiv.org/abs/2507.14710

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