Controlling quantum materials with light is of fundamental and technological importance. By utilizing the strong coupling of light and matter in optical cavities (1-3), recent studies were able to modify some of their most defining features (4-6). In this work, we study the magneto-optical properties of a van der Waals magnet that supports strong coupling of photons and excitons even in the absence of external cavity mirrors. In this material - the layered magnetic semiconductor CrSBr - emergent light-matter hybrids called polaritons are shown to significantly increase the spectral bandwidth of correlations between the magnetic, electronic, and optical properties, enabling largely tunable optical responses to applied magnetic fields and magnons. Our results highlight the importance of exciton-photon self-hybridization in van der Waals magnets and motivate novel directions for the manipulation of quantum material properties by strong light-matter coupling.
@article{arxiv.2301.07593,
title = {Magneto-optics in a van der Waals magnet tuned by self-hybridized polaritons},
author = {Florian Dirnberger and Jiamin Quan and Rezlind Bushati and Geoffrey Diederich and Matthias Florian and Julian Klein and Kseniia Mosina and Zdenek Sofer and Xiaodong Xu and Akashdeep Kamra and Francisco J. García-Vidal and Andrea Alù and Vinod M. Menon},
journal= {arXiv preprint arXiv:2301.07593},
year = {2024}
}