YRLG Workshop: Correlation and Topology in magnetic materials, July 16th - 18th 2024
Florian Dirnberger
Florian Dirnberger§ , 1, ∗ Sophia Terres§ , 1 Kseniia Mosina,2 Zdenek Sofer,2 Akashdeep Kamra,3 Mikhail. M. Glazov,4, 5 and Alexey Chernikov1
1Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Wrzburg-Dresden Cluster of Excellence ct.qmat, Dresden University of Technology, Dresden, 01187, Germany
2Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
3Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E- 28049 Madrid, Spain.
4 Ioffe Institute, 194021 Saint Petersburg, Russia 5National Research University, Higher School of Economics, 190121 Saint Petersburg, Russia
The recent discovery of magnetic excitons – a rare type of optical excitation that emerges from spin-polarized electronic states in magnets – raises fundamental questions about elemental interactions between excitons, magnons, and light. An important material for optical research in this regard is the layered antiferromagnetic semiconductor CrSBr. The great advantage of this material is that it supports robust and tightly bound excitons with strong responses to light [1], magnetic fields [2], and magnons [3] that provide access for experiments to explore the impact of magnons on the properties of excitons. In this contribution, we present the results of a study of the spatial transport of this intriguing type of exciton with particular focus on the role of crystal anisotropy, magnons and the magnetic order. We demonstrate highly non-linear exciton transport with unusual temperature dependence that culminates in substantially enhanced exciton propagation at the antiferromagnet-to-paramagnet phase transition. Observations of anomalous and effectively negative transport further indicate the substantial coupling of excitonic, vibronic, and magnetic degrees of freedom.
[1] Dirnberger, F. et al. Magneto-optics in a van der waals magnet tuned by self-hybridized polaritons. Nature 620, 533–537 (2023). [2] Wilson, N. P. et al. Interlayer electronic coupling on demand in a 2D magnetic semiconductor. Nature Materials 20, 1675 (2021). [3] Bae, Y. J. et al. Exciton-coupled coherent magnons in a 2D semiconductor. Nature 609, 282–286 (2022).