Chinese Physics B | 2021
Gilbert damping in the layered antiferromagnet CrCl3
Abstract
We theoretically and experimentally studied the Gilbert damping evolution of both acoustic and optical magnetic resonance modes in the layered flake CrCl3 with an external magnetic field H applied in plane. Based on a Lagrangian equation and a Rayleigh dissipation function, we predicted that the resonance linewidth ∆H as a function of microwave frequency ω is nonlinear for both acoustic and optical modes in the CrCl3 flake, which is significantly different from the linear relationship of ∆H ∝ ω in ferromagnets. By measuring the microwave transmission through the CrCl3 flake, we achieved the ω − H dispersion and damping evolution ∆H − ω for both acoustic and optical modes. Combining both our theoretical prediction and experimental observations, we concluded that the nonlinear damping evolution ∆H − ω is a consequence of the interlayer interaction during the antiferromagnetic resonance and the interlayer Gilbert dissipation plays an important role in the nonlinear damping evolution because of the asymmetry of the non-collinear magnetizaiton between layers.