Magneto-optics in a van der Waals magnet tuned by self-hybridized polaritons

TL;DR

This study demonstrates how self-hybridized polaritons in a van der Waals magnet can significantly enhance and tunably control its magneto-optical properties, opening new avenues for quantum material manipulation.

Contribution

It reveals the role of exciton-photon self-hybridization in van der Waals magnets, enabling tunable optical responses without external cavities.

Findings

Polaritons increase spectral bandwidth of magnetic correlations

Magneto-optical responses are tunable via magnetic fields and magnons

Self-hybridization enhances light-matter interaction in 2D magnetic materials

Abstract

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.