High Q‐factor anapole mode based on localized spoof surface plasmon polaritons

Abstract

Recently, localized spoof surface plasmon polaritons (LSSPPs) have emerged as a new research frontier due to their unique properties and potential applications in integrated circuits. The toroidal dipole is a localized electromagnetic response different from electric and magnetic dipoles. Anapole is the nonradiating source produced by the interference between identical radiation patterns of toroidal and electric dipoles in the far field. This paper proposes a novel high Q-factor compact planar resonator consisting of split-ring resonators to support the LSSPPs anapole at microwave frequency, which shows an apparent nonradiating charge-current configuration. In simulation and measurement, we observe the nonradiating property of the anapole mode. Further, we demonstrate that the LSSPPs anapole resonance has the tunable property, which is very sensitive to structural changes. These might lead to potential applications in the design of plasmonic deformation sensors, cloaking, and absorbers.