Anisotropic spin splitting in $α$-MnTe epilayers on InP(111)A and Si(111) substrates

Zofia Kopacz-Maj; Ali Akbar; Aleksandr Kazakov; Bartłomiej Turowski; Wojciech Zaleszczyk; Marta Aleszkiewicz; Tomasz Wojciechowski; Rafał Kurleto; Dawid Wutke; Natalia Olszowska; Tomasz Wojtowicz; Valentine V. Volobuev

arXiv · 2610.40850

Anisotropic spin splitting in $α$-MnTe epilayers on InP(111)A and Si(111) substrates

Zofia Kopacz-Maj·Ali Akbar·Aleksandr Kazakov·Bartłomiej Turowski·Wojciech Zaleszczyk·Marta Aleszkiewicz·Tomasz Wojciechowski·Rafał Kurleto·Dawid Wutke·Natalia Olszowska·Tomasz Wojtowicz·Valentine V. Volobuev

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Abstract

$α$-MnTe has emerged as a prototypical altermagnetic material, combining compensated antiferromagnetic order with momentum-dependent spin splitting. Here, we investigate the structural and electronic properties of epitaxial $α$-MnTe layers grown by molecular beam epitaxy on InP(111)A and Si(111) substrates. The crystalline and surface quality of the epilayers was characterised by reflection high-energy electron diffraction (RHEED), atomic force microscopy (AFM), and X-ray diffraction (XRD), confirming the formation of high-quality, single-phase films. The transport measurements were performed, confirming an antiferromagnetic transition and weak ferromagnetism. The electronic structure was studied using angle-resolved photoemission spectroscopy (ARPES). At 90 K, both samples exhibit relativistic anisotropic valence band splitting, which is substantially larger along the $Γ$-K direction, reaching approximately 300 meV, than along $Γ$-M, where values of about 150~meV are observed. The magnitude and momentum dependence of the splitting are very similar for $α$-MnTe grown on the two different substrates, indicating the robustness of the altermagnetic electronic structure with respect to the epitaxial environment.

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Zofia Kopacz-Maj, Ali Akbar, Aleksandr Kazakov, Bartłomiej Turowski, Wojciech Zaleszczyk, Marta Aleszkiewicz, Tomasz Wojciechowski, Rafał Kurleto, Dawid Wutke, Natalia Olszowska, Tomasz Wojtowicz, Valentine V. Volobuev. 2026-10-29. Anisotropic spin splitting in $α$-MnTe epilayers on InP(111)A and Si(111) substrates. https://arxiv.org/abs/2610.40850

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