Toroidal Localized Spoof Plasmons on Compact Metadisks

• Main Authors: Pengfei Qin, Yihao Yang, Muhyiddeen Yahya Musa, Bin Zheng, Zuojia Wang, Ran Hao, Wenyan Yin, Hongsheng Chen, Erping Li
• Format: Article
• Language: English
• Published: Wiley 2018-03-01
• Series: Advanced Science
• Subjects: localized spoof plasmons; metamaterials; toroidal dipoles
• Online Access: https://doi.org/10.1002/advs.201700487

Abstract Localized spoof surface plasmons (LSSPs) have recently emerged as a new research frontier due to their unique properties and increasing applications. Despite the importance, most of the current researches only focus on electric/magnetic LSSPs. Very recent research has revealed that toroidal LSSPs, LSSPs modes with multipole toroidal moments, can be achieved at a point defect in a 2D groove metal array. However, this metamaterial shows the limitations of large volume and poor compatibility to photonic integrated circuits. To overcome the above challenges, here it is proposed and experimentally demonstrated compact planar metadisks based on split ring resonators to support the toroidal LSSPs at microwave frequencies. Additionally, it is experimentally demonstrated that the toroidal LSSPs resonance is very sensitive to the structure changes and the background medium. These might facilitate its utilization in the design and application of plasmonic deformation sensors and the refractive index sensors.