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Updated: Jun 16, 2025
06:51
Microparticle Manipulation by Standing Surface Acoustic Waves with Dual-frequency Excitations
Published on: August 21, 2018
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Domain wall depinning from geometric notches using surface acoustic waves
Christopher Keck1, Anil Adhikari1, Shireen Adenwalla1
1Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588, United States of America.
Summary
Surface acoustic waves offer a novel method to control magnetic domain walls. This technique enhances depinning probability, even with low magnetic fields, presenting a feasible approach for technological applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Controlling magnetic domain wall motion is crucial for technological applications.
- Magnetic fields are effective but energetically costly and difficult to focus for domain wall depinning.
- Understanding pinning energy landscapes and driving forces is essential for reliable domain wall manipulation.
Purpose of the Study:
- To investigate the use of high-frequency surface acoustic waves (SAWs) to alter magnetic domain wall depinning probability.
- To explore strain-assisted depinning as an alternative to magnetic field-driven methods.
- To analyze the interplay between strain and magnetic fields in controlling domain wall motion at pinning sites.
Main Methods:
- Utilizing high-frequency surface acoustic waves to apply strain to Co/Pt heterostructures.
- Fabricating lithographically patterned notches to act as pinning sites for magnetic domain walls.
- Observing and quantifying the depinning probability of magnetic domain walls under combined strain and magnetic fields.
Main Results:
- Surface acoustic waves significantly alter the depinning probability of magnetic domain walls.
- Strain modifies pinning energies differently than magnetic fields, affecting domain wall energy but not Zeeman energy.
- A 100% depinning probability was achieved at low magnetic fields in the presence of strain waves.
Conclusions:
- Surface acoustic waves provide a novel, feasible method for controlling magnetic domain wall motion.
- Strain-assisted depinning offers an energetically efficient and focusable alternative to magnetic fields.
- The efficiency of depinning depends on the specific design of patterned pinning sites and the applied strain.
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