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arXiv · 2510.24376

Pseudo-Goldstone mode in altermagnetic $\alpha$-MnTe: high-field electron spin resonance studies

K. Yu. Povarov·J. Wosnitza·S. Rößler·M. Schmidt·A. A. Tsirlin·S. A. Zvyagin
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Abstract

We report multi-frequency electron spin resonance spectroscopy studies of $\alpha$-MnTe in magnetic fields up to $16$ T, applied along the easy anisotropy axis. At temperatures below $T_\mathrm{N} = 310$ K, we observe a single resonance line corresponding to the pseudo-Goldstone mode of the antiferromagnetic resonance (AFMR). This mode exhibits the isotropic behavior with $g_\mathrm{eff}=2.01$, consistent with a complete quench of the orbital angular momenta for Mn$^{2+}$ ions. At low temperatures, the resonance mode is remarkably narrow ($\sim50$ mT for the full width at the half-maximum at $5$ K). The AFMR mode exhibits substantial broadening with increasing temperature, which can be understood in terms of the magnon-magnon scattering

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K. Yu. Povarov, J. Wosnitza, S. Rößler, M. Schmidt, A. A. Tsirlin, S. A. Zvyagin. 2025-10-28. Pseudo-Goldstone mode in altermagnetic $\alpha$-MnTe: high-field electron spin resonance studies. https://doi.org/10.1103/wmdr-ctqb

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