Altermagnets and Odd-parity-wave magnets
The discovery of altermagnets was enabled by an unorthodox symmetry framework—crystallographic spin groups—allowing for the systematic classification of all collinear spontaneous exchange symmetry breakings [1,2]. This raises the questions of (i)whether they can be experimentally verified, (ii) whether more magnets with so far unknown symmetries and electronic structures can be realised, and (iii) whether such magnetic orders can be useful for spintronics.
In this talk, we answer these points in the affirmative. We first review altermagnetic symmetries, show theory-experiment verification of altermagnetism [3,4], and that it allows for spintronics effects such as giant magnetoresistance effects [5]. Then, we theoretically predict that odd-parity-wave orders emerge in noncentrosymmetric, noncollinear magnets with a combined translation and time-reversal symmetry [6]. Within these systems, we identify distinct subclasses, and here we will highlight the collinear order in the electronic band structure in coplanar systems, and p-wave order with one symmetry-enforced nodal surface. We then discuss that these systems can host giant transport anisotropy and Edelstein effects [6,7].
Contrary to common assumptions, we show that odd-parity-wave magnets can exhibit non-relativistic spin-split electronic band structures while preserving time-reversal symmetry—unlike ferromagnets and altermagnets, which break it. First-principles calculations and symmetry analysis predict large non-relativistic spin splittings and over 70 realistic material candidates for odd-parity-wave magnetism [6]. Our work opens a broad range of opportunities for exploring altermagnets and odd-parity-wave magnets, with potential applications in spintronics and topological physics.
[1] L Šmejkal, J Sinova, T Jungwirth, Phys. Rev. X 12, 031042 (2022), arXiv:2105.05820
[2] L Šmejkal, R González-Hernández, T Jungwirth, J Sinova, sciadv.aaz8809 (2020), arXiv:1901.00445
[3] J Krempaský, L Šmejkal, SW D’souza, M Hajlaoui, G Springholz, K Uhlířová, F Alarab, PC Constantinou, V Strocov, D Usanov, WR Pudelko, R González-Hernández, ABH, Z Jansa, H Reichlová, Z Šobáň, RD Gonzalez Betancourt, P Wadley, J Sinova, D Kriegner, J Minár, JH Dil, T Jungwirth. Nature 626, 517–522 (2024)
[4] S Reimers, L Odenbreit, L Šmejkal, V N Strocov, P Constantinou, ABH, R Jaeschke Ubiergo, W H Campos, V K Bharadwaj, A Chakraborty, T Denneulin, W Shi, R E Dunin-Borkowski, S Das, M Kläui, J Sinova, M Jourdan. Nat. Commun. 15, 2116 (2024)
[5] Šmejkal, ABH, R González-Hernández, J Sinova, T Jungwirth Phys. Rev. X 12, 011028 (2022), arXiv:2103.12664
[6] ABH, T Jungwirth, R Jaeschke-Ubiergo, A Chakraborty, J Sinova, L Šmejkal. arXiv:2309.01607v3
[7] A Chakraborty, ABH, R Jaeschke-Ubiergo, T Jungwirth, L Šmejkal, J Sinova. arXiv:2411.16378
About the qGAP meeting series
Welcome to qGAP, our seminar series on Quantum Physics and Quantum Technology.
The series of seminars/lectures are meant to cover broadly activities at UiO and elsewhere related to quantum physics and technologies, mainly from a theoretical perspective, though we also welcome experimental talks.
We aim at having regular seminars, discussions of recent articles, presentations by master and PhD students and more. We aim for this series to be a combination of research talks and journal clubs.
Educational topics are also most welcome.
Please feel free to suggest speakers, yourself included!
Get in touch with Gunnar Lange to suggest a speaker or if you would like to be included in the mailing list.
All are welcome!
Upcoming
- Tamás Havas & Olai Mostad (Simula UiB) June 6