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Nanoscale Mapping of Magnetic Auto-Oscillations with a Single Spin Sensor
Toni Hache1,2, Anshu Anshu1, Tetyana Shalomayeva2
1Max Planck Institute for Solid State Research, Heisenbergstr. 1, Stuttgart, 70569, Germany.
Nano Letters
|January 22, 2025
Summary
Spin Hall nano-oscillators create microwave magnetic auto-oscillations. Researchers mapped these dynamics, finding they localize at magnetic field minima, enabling better device engineering for energy-efficient hardware.
Area of Science:
- Condensed Matter Physics
- Spintronics
- Quantum Sensing
Background:
- Spin Hall nano-oscillators (SHNOs) convert DC to microwave magnetic auto-oscillations.
- SHNOs are key for energy-efficient communication hardware.
- Nanoscale mapping of SHNO dynamics has been a significant challenge.
Purpose of the Study:
- To image the spatial distribution of free-running magnetic auto-oscillations in SHNOs.
- To experimentally identify the physical locations of auto-oscillation spots.
- To understand the relationship between oscillation modes and magnetic field landscapes.
Main Methods:
- Utilized a single spin quantum sensor to image auto-oscillation dynamics.
- Employed electron spin resonance (ESR) transitions for sensor excitation.
- Achieved fast pixel acquisition rates (100 ms/pixel) for dynamic mapping.
- Performed quantitative magnetometry to analyze magnetic field distributions.
Main Results:
- Demonstrated that auto-oscillation spots are localized at magnetic field minima.
- Identified these minima as potential wells confining spin-waves.
- Correlated magnetic stray field magnitudes with different auto-oscillation frequencies.
- Provided the first experimental evidence of auto-oscillation localization.
Conclusions:
- The study reveals a direct link between magnetic potential wells and SHNO auto-oscillation localization.
- Insights into the interaction of auto-oscillation modes and spin-wave confinement are provided.
- Findings facilitate the advanced engineering of SHNO devices for improved performance.
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