Antiferromagnetic resonance in a bulk α-MnTe crystal is investigated using both frequency-domain and time-domain THz spectroscopy techniques. At low temperatures, an excitation at the photon energy of (3.5±0.1)~meV is observed and identified as a magnon mode through its distinctive dependence on temperature and magnetic field. This behavior is reproduced using a simplified model for antiferromagnetic resonance in an easy-plane antiferromagnet. The results of our experiments, when compared to exchange constants established in the literature, allow us to extract the out-of-plane component of the single-ion magnetic anisotropy reaching (40±10)~μeV.
@article{arxiv.2502.18933,
title = {Antiferromagnetic resonance in $\alpha$-MnTe},
author = {J. Dzian and P. Kubaščík and S. Tázlarů and M. Białek and M. Šindler and F. Le Mardelé and C. Kadlec and F. Kadlec and M. Gryglas-Borysiewicz and K. P. Kluczyk and A. Mycielski and P. Skupiński and J. Hejtmánek and R. Tesař and J. Železný and A. -L. Barra and C. Faugeras and J. Volný and K. Uhlířová and L. Nádvorník and M. Veis and K. Výborný and M. Orlita},
journal= {arXiv preprint arXiv:2502.18933},
year = {2025}
}