Harmonic Plasmonic Skyrmions with Time‐Varying Manipulation

ABSTRACT Plasmonic skyrmions, electromagnetic counterparts of topological quasiparticles, have recently shown nontrivial subwavelength features and promised topology‐enhanced information applications. However, these were only studied in linear wave systems until now, fundamentally distinct from the topological quasiparticles supported by strong nonlinearity in condensed matter. Here, we theoretically investigate and experimentally demonstrate the behavior of time‐dimensionally synthesized harmonic time‐varying skyrmions, revealing how temporal variations can effectively mimic the characteristics of nonlinear media to achieve frequency conversion. We examine the harmonic responses under typical time‐driven protocols and find that the frequency intervals of different skyrmion modes correspond to the time‐switching frequencies. Through experimental validation on our time‐varying platform, we successfully observe the emergence of harmonic skyrmions synthesized through the temporal dimension, with theoretical predictions corroborated by experimental results. Our findings pave the way for exploring harmonic skyrmions and provide new opportunities for interdisciplinary advancements at the intersection of topological physics and time‐varying systems.