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Dynamic oscillations of coupled domain walls
L O'Brien1, E R Lewis, A Fernández-Pacheco
1Thin Film Magnetism Group, Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom. lao24@cam.ac.uk
Physical Review Letters
|June 12, 2012
Summary
Nonlinearity in domain wall (DW) dynamics arises from intrinsic motion, not just potentials. This intrinsic nonlinearity is crucial for understanding DW behavior and must be considered in experiments.
Area of Science:
- Condensed matter physics
- Spintronics
- Nanomagnetics
Background:
- Distinguishing intrinsic nonlinearity (NL) from external perturbations in domain wall (DW) dynamics is challenging.
- Magnetostatically coupled DW systems offer a well-understood platform for studying DW behavior.
Purpose of the Study:
- To numerically investigate the dynamic oscillations of magnetostatically coupled DWs.
- To identify and characterize intrinsic nonlinearity in DW motion.
Main Methods:
- Numerical simulations of DW dynamics.
- Analysis of DW oscillations under harmonic potentials.
Main Results:
- Intrinsic NL observed in DW dynamics, even with harmonic potentials.
- NL is linked to DW canonical momentum terms, distinct from NL restoring potentials.
- This NL is not apparent in quasistatic measurements and is tunable via nanowire parameters.
Conclusions:
- Intrinsic DW motion contributes significantly to observed nonlinearity.
- This intrinsic NL is independent of the DW restoring potential and must be accounted for in potential landscape measurements.
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