We present the first ultrafast microscopy imaging study of a plasmonic spin skyrmion generated by the spin–orbit interaction of light. We reveal by experiment and theory the nanofemto plasmonic vortex fields and their topological skyrmion spin textures that can dress topologically trivial materials, drive magnetoelectric phenomena, and probe axion physics.
By ultrafast time-resolved PEEM macroscopic imaging, we record a lattice of topological plasmonic spin textures resembling a lattice of magnetic meron quasiparticles in a nano-patterned metallic square coupling structure. The robustness of the spin angular momentum texture over the excitation pulse duration is demonstrated by extracting deep subwavelength resolution images of linear polarization singularity distributions that define the meron domain boundaries.
Using time-resolved two-photon photoemission electron microscopy (PEEM), we experimentally recorded attosecond videos revealing evanescent vortex creations in a chiral plasmonic device even under linearly-polarized optical excitation. Moreover, the resulting vortex fields generate topological quasiparticles at the metal surface similar to magnetic skyrmions. We discover the stable creation of three plasmonic merons at the vortex core in the nano-femto scale.
A polarization-actuated circulator for surface plasmon polaritons (SPPs) is experimentally realized in the optical regime for the first time. We demonstrate circulations of SPPs can be actuated either by linearly polarized excitation or by spin angular momenta carried by circular polarizations. Experimentally, a wide optical operational bandwidth of ~ 100 nm is achieved.
A simple plasmonic nanostructure is designed to allow polarization‐sensitive directional steering of surface plasmon polaritons (SPPs). Based on crossed Babinet‐inverted nanoantennas, steering of SPPs in the full first quadrant with high sensitivity to the linear polarization of the monochromatic exciting source is numerically and experimentally demonstrated. The same device could also function as a polarization‐driven power‐splitter.