Presentation Information
[8a-E208-9]Electrical control of multimode spin-torque ferromagnetic resonance in a nearly isotropic magnet
〇(M1)Kano Ikegami1,2, Takaaki Dohi1, Aakanksha Sud1,3, Yuta Yamane1,3, Takeshi Tasaki1,2, Vihanga De Zoysa1, Shoji Ikeda2,8, Shun Kanai1,2,4,5,6,7, Shunsuke Fukami1,2,4,5,8,9 (1.Tohoku Univ., 2.RIEC, Tohoku Univ., 3.FRIS, Tohoku Univ., 4.AIMR, Tohoku Univ., 5.CSIS, Tohoku Univ., 6.DEFS, Tohoku Univ., 7.QST, 8.CIES, Tohoku Univ., 9.InaRIS)
Keywords:
ST-FMR,Spin-Orbit Torque,Nonlinear Magnetization Dynamics
Spin–orbit torque (SOT) enables efficient electrical control of magnetization and is a key mechanism for next-generation spintronic devices. In this presentation, we report nonlinear spin-torque ferromagnetic resonance (ST-FMR) in nearly isotropic W/CoFeB/MgO/Ta heterostructures, where the interfacial perpendicular magnetic anisotropy almost compensates the demagnetizing field. Such a magnetic configuration provides weak restoring torque, allowing large-amplitude magnetization dynamics and enhanced nonlinear effects.
We investigate the evolution of the ST-FMR spectra as a function of magnetic field and DC current. The measurements reveal pronounced nonlinear behaviors, including asymmetric resonance-line distortion, spectral broadening, and the emergence of multimode responses. In particular, a two-peak resonance structure appears at higher magnetic fields, accompanied by asymmetric redistribution of spectral intensity between the modes. The resonance characteristics strongly depend on the polarity of the applied DC current, indicating electrical control of the nonlinear dynamical state.
These observations suggest the presence of nonlinear mode interactions and instability-driven multimode dynamics in nearly isotropic magnetic systems. The results demonstrate that nearly isotropic SOT devices provide a useful platform for exploring nonlinear spin dynamics, mode coupling, and dissipation-controlled magnetic resonance phenomena.
We investigate the evolution of the ST-FMR spectra as a function of magnetic field and DC current. The measurements reveal pronounced nonlinear behaviors, including asymmetric resonance-line distortion, spectral broadening, and the emergence of multimode responses. In particular, a two-peak resonance structure appears at higher magnetic fields, accompanied by asymmetric redistribution of spectral intensity between the modes. The resonance characteristics strongly depend on the polarity of the applied DC current, indicating electrical control of the nonlinear dynamical state.
These observations suggest the presence of nonlinear mode interactions and instability-driven multimode dynamics in nearly isotropic magnetic systems. The results demonstrate that nearly isotropic SOT devices provide a useful platform for exploring nonlinear spin dynamics, mode coupling, and dissipation-controlled magnetic resonance phenomena.