C4: Ultrastrong matter-magnon coupling phenomena

Joachim Deisenhofer, Marcus Kollar

In this project we will explore ultrastrong coupling (USC) effects in the polar magnets A2Mo3O8 with A = Fe, Co, Mn, Zn and in the rare-earth orthoferrites REFeO3 (RE = Tm, Er, Y) using THz-time-domain spectroscopy in external magnetic fields. We will identify further material classes to clarify the origin of the USC and the involved bosonic states. New non-equilibrium phenomena will be investigated using intense coherent THz fields. We will develop a theoretical description in terms of quantum Rabi-type models using input from the THz data. Their complexity will depend on the importance of counter-rotating terms and the presence of asymmetric terms due to broken inversion symmetry. Numerical and analytical studies of these models will help to clarify the origin of the USC.

Publications

2023

Ghara, S.; Barts, E.; Vasin, K.; Kamenskyi, D.; Prodan, L.; Tsurkan, V.; Kézsmárki, I.; Mostovoy, M.; Deisenhofer, J.

Magnetization reversal through an antiferromagnetic state Journal Article

Nat. Commun. 14, 5174, 2023.

Abstract | Links | BibTeX

Magnetization reversal through an antiferromagnetic state