Spin-Orbit Torque Nano-oscillators by Dipole-Field-Localized Spin Wave Modes

We demonstrate a high-quality spin-orbit torque nano-oscillator comprised of spin wave modes confined by the magnetic field by the strongly inhomogeneous dipole field of a nearby micromagnet. This approach enables variable spatial confinement and systematic tuning of magnon spectrum and spectral separations for studying the impact of multimode interactions on auto-oscillations. We find these dipole-field-localized spin wave modes exhibit good characteristic properties as auto-oscillators-narrow line width and large amplitude-while persisting up to room temperature. We find that the line width of the lowest-lying localized mode is approximately proportional to temperature in good agreement with theoretical analysis of the impact of thermal fluctuations. This demonstration of a clean oscillator with tunable properties provides a powerful tool for understanding the fundamental limitations and line width contributions to improve future spin-Hall oscillators.

Automated summary

The research team demonstrated a high-quality spin-orbit torque nano-oscillator consisting of spin wave modes confined by the strongly inhomogeneous dipole field of a nearby micromagnet. This approach allows for variable spatial confinement and systematic tuning of magnon spectrum and spectral separations to study the impact of multimode interactions on auto-oscillations. The dipole-field-localized spin wave modes exhibit favorable characteristic properties as auto-oscillators, with narrow line width and large amplitude, persisting up to room temperature.