Time-resolved imaging of magnetic vortex dynamics using holography with extended reference autocorrelation by linear...

Area of Science:

• Physics
• Materials Science
• Magnetism

Background:

• Magnetic thin-film elements exhibit complex magnetisation dynamics.
• Understanding domain wall behavior is crucial for magnetic device applications.

Purpose of the Study:

• To investigate the structure and dynamics of domain walls in magnetic thin films using time-resolved X-ray measurements.
• To explore the influence of pulsed magnetic fields on magnetisation dynamics.

Main Methods:

• Holography with Extended Reference Autocorrelation by Linear Differential Operator (HERALDO) for time-resolved X-ray measurements.
• Excitation using nanosecond pulsed magnetic fields.
• Numerical simulations to analyze singularity formation and dynamics.

Main Results:

• Demonstrated dynamic changes in the perpendicular magnetisation component of domain walls.
• Observed wave bullet-like excitations propagating within domain walls during vortex core motion.
• Identified four corner singularities whose polarisation is linked to the vortex core and can be switched by wave bullets.

Conclusions:

• The magnetisation dynamics of domain walls are influenced by pulsed magnetic field parameters.
• Wave bullets play a key role in switching singularity polarisations and affect Landau pattern evolution.
• The study provides new insights into the complex interplay between vortex core, domain walls, and singularities in magnetic thin films.