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Spin-Hall-effect-modulation skyrmion oscillator
Hyun-Seok Whang1, Sug-Bong Choe2
1Department of Physics and Institute of Applied Physics, Seoul National University, Seoul, 08826, Republic of Korea.
Scientific Reports
|July 21, 2020
Summary
Researchers developed a novel skyrmion-based spin-torque oscillator. This new device utilizes the spin-Hall effect (SHE) for tunable GHz oscillations, potentially overcoming limitations of current spintronic devices.
Area of Science:
- Spintronics
- Condensed Matter Physics
- Materials Science
Background:
- Electric-current-induced spin torque enables electric control of magnetization, crucial for spintronic devices.
- Nanoscale spin-torque oscillators (STOs) using spin-polarized current offer GHz tunability but face challenges in output power, linewidth, and magnetic-field-free operation.
Purpose of the Study:
- To propose and investigate a new concept for a spin-torque oscillator based on magnetic skyrmion dynamics.
- To address the limitations of conventional spin-torque oscillators by leveraging the spin-Hall effect (SHE).
Main Methods:
- Proposed a novel STO concept utilizing magnetic skyrmion dynamics.
- Incorporated lateral modulation of the spin-Hall effect (SHE) to create regions with opposite SHE-torque.
- Employed micromagnetic simulations to confirm skyrmion oscillations.
Main Results:
- Demonstrated skyrmion circulation around the modulation boundary due to SHE-induced forces.
- Achieved oscillation frequencies up to 15 GHz in synthetic ferrimagnet media.
- Confirmed the robustness and speed of the proposed SHE-modulation-based skyrmion oscillator.
Conclusions:
- The proposed SHE-modulation-based skyrmion oscillator presents a promising new avenue for spintronic devices.
- This approach is expected to overcome key limitations of conventional spin-torque oscillators, such as output power and linewidth.
- The high-frequency operation and robustness suggest potential for advanced applications in high-frequency electronics.
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