Sud A, Yamamoto K, Iihama S, Ishibashi K, Fukami S, Kurebayashi H, Mizukami S
Tohoku University, Frontier Research Institute for Interdisciplinary Sciences, 6-3 Aoba, Sendai 980-8578, Japan.
Tohoku University, Research Institute of Electrical Communication, 2-1-1 Katahira, Sendai 980-8577, Japan.
Phys Rev Lett. 2025 Jun 20;134(24):246704. doi: 10.1103/sc6y-rxbg.
We investigate the nonlinear coupling between acoustic (ac) and optical (op) modes in the coupled magnetization dynamics of synthetic antiferromagnets, utilizing current-driven resonance spectroscopy. A clear spectral splitting is evident in the ac mode when strongly excited by the radio frequency current at a driving frequency half that of the op mode resonance. The Landau-Lifshitz phenomenology aligns with the experimental observations, affirming the coupling of the radio-frequency-excited ac and op modes through three-magnon mixing. The nonlinearity enables a Rabi-like splitting in an in-plane magnetized synthetic antiferromagnet without breaking its natural symmetries. This discovery holds potential for advancing our understanding of nonlinear antiferromagnetic dynamics.
我们利用电流驱动共振光谱研究了合成反铁磁体耦合磁化动力学中声学（ac）和光学（op）模式之间的非线性耦合。当以op模式共振频率一半的驱动频率受到射频电流强烈激发时，ac模式中会出现明显的光谱分裂。朗道 - 里夫希茨现象学与实验观测结果相符，证实了射频激发的ac和op模式通过三磁振子混合实现耦合。这种非线性使得面内磁化的合成反铁磁体中出现类似拉比分裂的现象，同时又不破坏其固有对称性。这一发现对于推进我们对非线性反铁磁动力学的理解具有潜在意义。
