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Spin transfer torque driven higher-order propagating spin waves in nano-contact magnetic tunnel junctions
A Houshang1,2, R Khymyn1, H Fulara1
1Physics Department, University of Gothenburg, 412 96, Gothenburg, Sweden.
Nature Communications
|October 24, 2018
Summary
Researchers generated shorter spin waves using magnetic tunnel junctions, enabling faster, more efficient magnonic devices. This breakthrough paves the way for advanced high-frequency data transmission in spintronics.
Area of Science:
- Spintronics
- Condensed Matter Physics
- Materials Science
Background:
- Short wavelength spin waves are crucial for high-frequency magnonic devices and data transmission.
- Giant magnetoresistance (GMR) nanocontacts generate spin waves but with limited wavelengths and signal strength.
Purpose of the Study:
- To demonstrate efficient generation of short wavelength spin waves using magnetic tunnel junctions.
- To explore the potential of higher-order spin wave modes for magnonic applications.
Main Methods:
- Fabrication of nano-contact based magnetic tunnel junctions.
- Electrical characterization of spin wave generation and propagation.
- Analysis of frequency-dependent spin wave properties.
Main Results:
- Observed generation of second- and third-order spin waves with wavelengths significantly smaller than the nanocontact diameter (120 nm and 74 nm).
- Demonstrated mutual synchronization across all three propagating spin wave modes.
- Achieved higher group velocities for these higher-order modes.
Conclusions:
- Magnetic tunnel junctions are effective for generating short wavelength, high-frequency spin waves.
- Higher-order spin waves offer a pathway to significantly enhance magnonic device performance, including data rates and propagation lengths.
- Synchronization of multiple spin wave modes opens possibilities for complex signal processing.
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