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

Abstract

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 μ 0 H E = 0.395(2) T, and the hard and intermediate-axis anisotropy parameters are μ 0 H c = 1.30(2) T and μ 0 H 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.

Anisotropy in Multiferroic CuCrP2S6

“…4a, there is a single peak in microwave absorption among all the frequencies, with gradual and linear shift from 0.1 T to 0.5 T as increasing the resonance frequency. It reveals an obvious electron paramagnetic resonance signal, which could be well tted by Kittel equations 41,42 . The resonance in 100 K indicates similar behavior with that in 50 K (see Supplementary Fig.…”

“…It is widely assumed that uniaxial magnetic anisotropy is critical for achieving ultrafast spin transfer and e cient spin-wave excitation in an antiferromagnet 41 . To investigate the magnon modes coming from magnetic anisotropy and SF transition, ferromagnetic resonance (FMR) measurements were proceeded at different temperatures and magnetic elds.…”

Electrical and magnetic anisotropies in van der Waals multiferroic CuCrP2S6

“…We observed all the microwave absorption spectra in the frequency range of 3–13 GHz. The much lower frequency compared to traditional antiferromagnets is because of the dominant weak interlayer AFM coupling 43 . The representative resonances of 50 K and 10 K along the a axis are shown in Fig.…”

“…It is widely assumed that uniaxial magnetic anisotropy is critical for achieving ultrafast spin transfer and efficient spin-wave excitation in an antiferromagnet 40 – 43 . To investigate the magnon modes coming from the magnetic anisotropy and the SF transition, antiferromagnetic resonance (AFMR) measurements were proceeded at different temperatures and magnetic fields.…”

“…3d . The Landau−Lifshitz model for A-type AFM vdW crystal lattices 43 has been carried out to fit the frequency vs field data at 10 K, in order to determine the parameters of magnetic anisotropy in CCPS. As magnetic field is parallel to the a axis within the vdW layer, the spin orders initially stay anti-parallel to each other and align along this easy axis.…”