Anisotropic excitons in van der Waals magnet CrSBr

We report anisotropic excitons in few layer van der Waals magnet CrSBr, where excitons serve as the main carriers of optical excitations. In addition to the well-documented exciton around 900 nm (1.37 eV), we identify a previously unreported higher energy exciton at 700 nm (1.77 eV) through absorption spectrum analysis. A key facet of our investigation involves the application of polarization-resolved photoluminescence excitation (PLE) spectroscopy to comprehensively understand the anisotropic attributes excitons in thin CrSBr. Furthermore, our research reveals different behaviors of these excitons with respect to their response to antiferromagnetic resonances, by subjecting the sample to a magnetic field and analyzing both photoluminescence and absorption spectrum. This work advances our understanding of van der Waals magnet CrSBr and their potential application in emerging technologies.