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arXiv · 2603.21455

Band structure control in the altermagnetic candidate MnTe by temperature and strain

Shin-ichi Kimura·Hironao Suwa·Kangle Yuan·Hiroshi Watanabe·Takuto Nakamura·Haan Kyul Yun·Myung-Hwa Jung
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Abstract

The temperature and strain dependences of the optical conductivity spectrum of hexagonal manganese telluride (MnTe) were measured, revealing absorption in the terahertz (THz) region from spin-split bands to acceptor levels. The temperature dependence of the THz absorption peak is consistent with that of a ferromagnetic phase transition, even though MnTe exhibits no net magnetism. The temperature dependence was attributed to a change in the altermagnetic electronic structure. A Fano-like antisymmetric line shape in the optical phonon absorption was observed, which originates from the interaction between optical phonons and the spin-split bands. Additionally, under negative uniaxial pressure, the THz peak shifts away from the Fermi level (EF), suggesting that spin-splitting bands at energies away from EF, consistent with the theoretical prediction that the spin-splitting angle decreases. The observed behavior of the THz peak clearly shows that MnTe has the altermagnetic electronic structure.

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Shin-ichi Kimura, Hironao Suwa, Kangle Yuan, Hiroshi Watanabe, Takuto Nakamura, Haan Kyul Yun, Myung-Hwa Jung. 2026-03-23. Band structure control in the altermagnetic candidate MnTe by temperature and strain. https://arxiv.org/abs/2603.21455

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