Magnetostatic effect on spin dynamics properties in antiferromagnetic Van der Waals material CrSBr

TL;DR

This study investigates how magnetostatic effects influence spin dynamics in the antiferromagnetic van der Waals material CrSBr, revealing orientation-dependent resonance modes and highlighting the importance of dipolar interactions in 2D antiferromagnets.

Contribution

It uncovers the role of magnetostatic effects in spin dynamics of CrSBr, demonstrating orientation-dependent resonance modes and emphasizing dipolar interactions in 2D AFM materials.

Findings

Observation of a dipolar spin wave mode in CrSBr.

Resonance modes depend on microwave field orientation.

Magnetostatic effects explain orientation dependence.

Abstract

Van der Waals (vdW) antiferromagnets are exceptional platforms for exploring the spin dynamics of antiferromagnetic materials owing to their weak interlayer exchange coupling. In this study, we examined the antiferromagnetic resonance spectra of anisotropic Van der Waals antiferromagnet CrSBr. In addition to the ordinary resonance modes, we observed a dipolar spin wave mode when the microwave field was oriented perpendicular to the in-plane easy axis of CrSBr. Furthermore, our results uncovered a pronounced dependency of various resonant modes on the orientation of the microwave field, which is pivotal for the accurate determination of exchange coupling constants. Numerical simulations have elucidated this orientation dependence of spin dynamics arises from the magnetostatic effect. This discovery underscores the previously underappreciated significance of dipolar interactions in shaping the dynamical properties of two-dimensional AFM materials, thereby enhancing our understanding of the intrinsic dynamic properties of vdW magnets.