SPICE Workshop on Ferrons and Magnons: friends or foes? July 7th - 9th, 2026
Alexander Mook
Recent years have witnessed the discovery of unconventional magnetic phases that challenge the traditional distinction between ferromagnets and antiferromagnets [1–4]. Among them, altermagnets and antialtermagnets exhibit novel symmetry properties that strongly influence their collective excitations. In this talk, I will discuss recent advances in the theory of magnons and related collective modes in these systems. Topics include the emergence of altermagnetism from orbital order [5], spin-demon excitations in d-wave altermagnets [6], spontaneous magnon decay enabled by spin-split magnon bands [7,8], and unconventional magnon–phonon coupling leading to textured phonon angular momentum [9]. I will further highlight recent developments in altermagnetic surface physics [10] and in antialtermagnets, where magnons can exhibit odd-parity spin splitting [11,12]. These results establish unconventional magnets as a fertile platform for exploring new quasiparticles and dynamical effects beyond conventional spin-wave physics.
References
[1] L. Šmejkal, J. Sinova, and T. Jungwirth, Phys. Rev. X 12, 031042 (2022).[2] L. Šmejkal, J. Sinova, and T. Jungwirth, Phys. Rev. X 12, 040501 (2022).
[3] A. B. Hellenes et al., arXiv:2309.01607 (2023).
[4] T. Jungwirth et al., Newton 1, 100162 (2025).
[5] V. Leeb, A. Mook, L. Šmejkal, and J. Knolle, Phys. Rev. Lett. 132, 236701 (2024).
[6] P. M. Gunnink, J. Sinova, and A. Mook, Phys. Rev. Lett. 135, 126701 (2025).
[7] R. Hoyer et al., Phys. Rev. B 112, 064425 (2025).
[8] R. Eto et al., Phys. Rev. B 112, 094442 (2025).
[9] H. Bendin, A. Mook, I. Mertig, and R. R. Neumann, arXiv:2511.08357 (2025).
[10] C. Lange, R. Jaeschke-Ubiergo, A. Chakraborty, X. H. Verbeek, L. Šmejkal, J. Sinova, A. Mook, arXiv:2602.08773 (2026).
[11] R. R. Neumann, R. Jaeschke-Ubiergo, R. Zarzuela, L. Šmejkal, J. Sinova, A. Mook, arXiv:2603.05415 (2026)
[12] V. P. Kravchuk, K. V. Yershov, B. Pradenas, R. R. Neumann, R. Jaeschke-Ubiergo, R. Zarzuela, J. Sinova, J. van den Brink, A. Mook, arXiv:2605.22614 (2026)