The Joint Condensed Matter Seminar (JCMS) series is organised by KTH Royal Insitute of Technology, Nordita, and Stockholm University.
On Monday, November 11th, 2026 from 10:15 to 10:15 we will host a seminar by Matteo Dürrnagel from University of Würzburg.
Exotic ordering mechanisms from non-symmorphic momentum space symmetries
In this talk I will promote systems with projective symmetry representations as promising platforms for novel quantum many body phases. A projective factor system in real space can give rise to a non-symmorphic space group representation in momentum space with direct consequences for the symmetry allowed ordering tendencies of the system. I will exemplify their potential on two recent examples – extended s-wave altermagnetism [1] and nodeless pair density wave order [2] – and discuss both their microscopic formation mechanisms as well as experimentally traceable signatures. Finally, I will highlight the relevance of our results for newly synthesized M-point twisted moiré materials and magnetic systems hosting emergent projective symmetry representations in their effective low energy description.
[1] M. Dürrnagel, L. Klebl, T. Müller, R. Thomale, and M. Klett, Extended s-wave altermagnets, arXiv 2508.20163 (2025) [2] M. Dürrnagel, C. A. Baum, M. Klett, L. Klebl, and R. Thomale, Pair density wave order from non-symmorphic momentum symmetry, arXiv 2609.05603 (2026)