Stana Tazlaru (FZU and Charles University, Czech Republic)
at 11 o'clock room 022 (Appelstraße 2, Building 3701)
Manganese telluride (MnTe) is a relatively well-studied material [1] whose antiferromagnetic and semiconducting properties make it relevant for various applications, notably for spintronics [2]. Renewed interest in its study arose with recent experimental observations comprising of the anomalous Hall effect [3], anisotropic magnetoresistance [4] and of its altermagnetic character [5]. The first part of the talk will provide an overview of our current understanding of the material.
In the second part, introduction to a magnonic physics with emphasis on a qualitative behaviour and general patterns will be given, starting with classical macrospin structure and spin wave picture, leading up to a linear spin wave theory (LSWT) and its predictions for magnon dispersion spectra. Lastly, results of two THz spectroscopy measurement of k = 0 (i.e. Γ-point) magnons in the presence of an external magnetic field will be discussed and analysed in the context of presented theoretical framework and MnTe hard-axis anisotropy determination will be demonstrated.
References
[1] J. Allen, G. Lucovsky, and J. Mikkelsen, Optical properties and electronic structure of crossroads material MnTe, Solid State Commun. 24, 367 (1977).
[2] V. Baltz, A. Manchon, M. Tsoi, T. Moriyama, T. Ono, and Y. Tserkovnyak, Antiferromagnetic spintronics, Rev. Mod. Phys. 90, 015005 (2018).
[3] N. Nagaosa, J. Sinova, S. Onoda, A. H. MacDonald, and N. P. Ong, Anomalous Hall effect, Rev. Mod. Phys. 82, 1539 (2010).
[4] P. Ritzinger and K. Vyborny, Anisotropic magnetoresistance: materials, models and applications, R. Soc. Open Sci. 10, 230564 (2023).
[5] Z. Liu, M. Ozeki, S. Asai, S. Itoh, and T. Masuda, Chiral split magnon in altermagnetic MnTe, Phys. Rev. Lett. 133, 156702 (2024).