Fig. 1: LSP skyrmions with robust topological features and near-equidistant multi-resonant responses supported by ultrathin space-coiling meta-structures.
The space-coiling meta-structures made of a single-armed metallic spiral strip with pitch size d, gap width a, radius R and number of turns nr are shown on the left. The vectorial magnetic field configurations of their supported modes are shown on the right. The space-coiling meta-structures support a train of deeply subwavelength LSP modes with near-equidistant multi-resonant response, whose vectorial magnetic field configurations are characterized by elementary skyrmion, skyrmionium and multiple-π-twist TS, with fundamental resonance frequency f0, FSR Δf, and skyrmion number S = 1 for odd modes and S = 0 for even modes (middle panel). The skyrmion topology is robust against continuous deformations of the geometry, e.g., from round (upper panel) to asymmetric heart shape (lower panel).
