Synthetic spin dynamics with Bessel-Gaussian optical skyrmions

Area of Science:

• Topological physics
• Optical physics
• Nonlinear optics

Background:

• Skyrmions are topologically stable field configurations with integer topological invariants (Skyrme number).
• They have been explored in magnetic and optical systems as 2D and 3D structures.
• Understanding skyrmion dynamics is crucial for their application in advanced technologies.

Purpose of the Study:

• To introduce and demonstrate an optical analogy to magnetic skyrmions.
• To investigate the dynamics and controllable precession of these optical skyrmions.
• To explore the potential for optical control of systems analogous to solid-state magnetic systems.

Main Methods:

• Engineered optical skyrmions and a synthetic magnetic field using superpositions of Bessel-Gaussian beams.
• Observed time dynamics of optical skyrmions over propagation distance.
• Utilized full Stokes analysis to monitor the Skyrme number invariance.

Main Results:

• Demonstrated controllable periodic precession of optical skyrmions during propagation.
• Observed that local precession manifests as global beating between skyrmion types.
• Confirmed the invariance of the Skyrme number throughout the dynamics.

Conclusions:

• The study successfully created and characterized optical skyrmions with dynamics analogous to magnetic skyrmions.
• The findings show potential for free-space optical control of topological fields.
• Numerical simulations suggest this approach can be extended to create time-varying magnetic fields.