YRLG Workshop: Correlation and Topology in magnetic materials, July 16th - 18th 2024
Biswajit Datta
Semiconducting van der Waals materials with a direct band gap, exhibiting both light emission and magnetic order, hold significant promise for applications in spintronic and magneto-optical devices. Among these materials, CrSBr stands out due to its remarkable properties, including substantial optical anisotropy, magnetic field-tunable magnetic order and exciton energy, and linearly polarized photoluminescence (PL). Despite supporting multiple excitons, the specific nature of these excitons and their magnetic states remains elusive. We study the two excitons with the highest oscillator strength that occur at 910 nm and 700 nm. First, I will present our findings focusing on the high-energy 700 nm exciton. Through magnetic field and power-dependent differential reflection measurements, we elucidate their Frenkel and Wannier character. Additionally, we demonstrate large light-matter coupling strength of the 700 nm exciton, manifested in a pronounced exciton-polariton Rabi splitting within a microcavity. In the second part, leveraging a cavity, we will control the propagation of these polaritons. Our study underscores CrSBr as an outstanding platform for the development of innovative photonic devices.