Anisotropic Gigahertz Antiferromagnetic Resonances of the Easy-Axis van der Waals Antiferromagnet CrSBr

We report measurements of antiferromagnetic resonances in the van der Waals easy-axis antiferromagnet CrSBr. The interlayer exchange field and magnetocrystalline anisotropy fields are comparable to laboratory magnetic fields, allowing a rich variety of gigahertz-frequency dynamical modes to be accessed. By mapping the resonance frequencies as a function of the magnitude and angle of applied magnetic field, we identify the different regimes of antiferromagnetic dynamics. The spectra show good agreement with a Landau-Lifshitz model for two antiferromagnetically coupled sublattices, accounting for interlayer exchange and triaxial magnetic anisotropy. Fits allow us to quantify the parameters governing the magnetic dynamics: At 5 K, the interlayer exchange field is mu H-0(E) = 0.395(2) T, and the hard and intermediate-axis anisotropy parameters are mu H-0(c) = 1.30(2) T and mu H-0(a) = 0.383(7) T. The existence of within-plane anisotropy makes it possible to control the degree of hybridization between the antiferromagnetic resonances using an in-plane magnetic field.

Automated summary

In this study, measurements of antiferromagnetic resonances in CrSBr were reported, different regimes of antiferromagnetic dynamics were identified through variations in magnetic field parameters, fitting parameters were quantified and the influence on magnetic dynamics was discussed, showing the possibility of controlling the degree of hybridization between antiferromagnetic resonances using an in-plane magnetic field.