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Published on: July 2, 2018
Magnetic antivortex-core reversal by circular-rotational spin currents.
Thomas Kamionka1, Michael Martens, Kang Wei Chou
1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, 20355 Hamburg, Germany. tkamionk@physnet.uni-hamburg.de
Physical Review Letters
|January 15, 2011
Summary
Topological antivortices in magnetic films are 2D oscillators. Researchers observed purely spin-torque induced antivortex-core reversal, suppressing Oersted field coupling for precise control.
Area of Science:
- Condensed Matter Physics
- Spintronics
- Materials Science
Background:
- Topological singularities, specifically antivortices, exist in ferromagnetic thin films.
- Antivortices function as 2D oscillators with a gyrotropic eigenmode.
- This mode is excitable via resonant spin currents and magnetic fields.
Purpose of the Study:
- Investigate the coupling between spin currents and magnetic fields in exciting antivortices.
- Demonstrate the selective excitation of the antivortex gyrotropic eigenmode.
- Achieve controlled antivortex-core reversal using spin-torque effects.
Main Methods:
- Utilized time-resolved scanning transmission X-ray microscopy (TR-TXM).
- Imaged the dynamic response of isolated antivortices.
- Employed circular-rotational spin currents for excitation.
Main Results:
- Observed coupling between spin current and magnetic field excitation in opposing rotational senses.
- Demonstrated suppression of Oersted field coupling when current rotation matches antivortex gyration.
- Reported the experimental observation of purely spin-torque induced antivortex-core reversal.
Conclusions:
- Spin-torque excitation can selectively drive antivortex dynamics.
- Precise control over antivortex-core reversal is achievable by managing excitation conditions.
- TR-TXM is effective for nanoscale dynamic imaging of magnetic structures.
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