Photonic Spin Skyrmion With Dynamic Position Control

Skyrmions are topological spin structures with broad application prospects in magnetic information storage and spintronics. Besides in magnetic materials, Skyrmions are observed in various photonic systems, demonstrating new deep-subwavelength characteristics. While the dynamic motion control of the magnetic Skyrmions has been achieved through many techniques, studies on the manipulation of the photonic Skyrmion have rarely been done. Here, we show dynamic position control of photonic Skyrmion with the use of a phase profile imposed by a spatial light modulator. The photonic Skyrmions are generated by the spin-orbit coupling in the surface plasmon polariton field, and the spin textures are mapped through a nanoparticle-on-film configuration. The photonic Skyrmions are experimentally shown to be shifted flexibly in two dimensions, with precise position control and almost no distortion of the spin textures. In addition, the locking of the shifting directions to the Skyrmion chirality is observed when a liquid crystal plate is employed to provide the phase profile instead of the spatial light modulator. The proposed technique realizes the mapping of the spin angular momentum of the photonic Skyrmion with dynamic position control for the first time, which is expected to be valuable for future applications in optical information storage and transfer.