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Spin-Orbit Torque Nano-oscillators by Dipole-Field-Localized Spin Wave Modes
Chi Zhang1, Inhee Lee1, Yong Pu1
1Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States.
Nano Letters
|December 6, 2021
Summary
We developed a novel spin-orbit torque nano-oscillator using magnetic fields for tunable spin wave confinement. This device shows promise for advancing spin-Hall oscillator technology by enabling detailed studies of auto-oscillation dynamics.
Area of Science:
- Condensed Matter Physics
- Spintronics
- Nanotechnology
Background:
- Spin-orbit torque (SOT) devices are crucial for next-generation electronics.
- Understanding spin wave dynamics is key to improving SOT nano-oscillators.
- Controlling spin wave confinement is essential for device performance.
Purpose of the Study:
- To demonstrate a high-quality SOT nano-oscillator with tunable spin wave confinement.
- To investigate the impact of multimode interactions on auto-oscillations.
- To provide a platform for studying thermal fluctuation effects on oscillator linewidth.
Main Methods:
- Utilizing the inhomogeneous dipole field of a nearby micromagnet to confine spin wave modes.
- Spatial confinement and tuning of magnon spectrum and spectral separations.
- Measuring linewidth and amplitude characteristics of localized spin wave modes.
Main Results:
- Achieved a high-quality SOT nano-oscillator with tunable spatial confinement.
- Localized spin wave modes exhibited narrow linewidths and large amplitudes, persisting up to room temperature.
- The linewidth of the lowest-lying localized mode showed approximate proportionality to temperature, aligning with theoretical predictions.
Conclusions:
- Demonstrated a clean, tunable oscillator for studying auto-oscillation dynamics.
- The findings provide insights into fundamental limitations and linewidth contributions in SOT devices.
- This work offers a powerful tool for the development of improved spin-Hall oscillators.
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