Hyperbolic spoof plasmonic metasurfaces

Yihao Yang,Huaping Wang,Liqiao Jing,Thomas Koschny,Costas M Soukoulis,Hongsheng Chen,Lian Shen,Bin Zheng,Nian-Hai Shen,Erping Li,Zuojia Wang

doi:10.1038/am.2017.158

Abstract

Hyperbolic metasurfaces have recently emerged as a new research frontier because of the unprecedented capabilities to manipulate surface plasmon polaritons (SPPs) and many potential applications. However, thus far, the existence of hyperbolic metasurfaces has neither been observed nor predicted at low frequencies because noble metals cannot support SPPs at longer wavelengths. Here, we propose and experimentally demonstrate spoof plasmonic metasurfaces with a hyperbolic dispersion, where the spoof SPPs propagate on complementary H-shaped, perfectly conducting surfaces at low frequencies. Thus, non-divergent diffractions, negative refraction and dispersion-dependent spin-momentum locking are observed as the spoof SPPs travel over the hyperbolic spoof plasmonic metasurfaces (HSPMs). The HSPMs provide fundamental new platforms to explore the propagation and spin of spoof SPPs. They show great capabilities for designing advanced surface wave devices such as spatial multiplexers, focusing and imaging devices, planar hyperlenses, and dispersion-dependent directional couplers, at both microwave and terahertz frequencies.

Highlights

Metamaterial is an artificial material with subwavelength unit cells that exhibit unusual properties that are never found in nature.[1]
Because the three-dimensional hyperbolic metamaterials suffer from large volume, complexity of fabrication and considerable propagation losses,[9] hyperbolic metasurfaces have been reported with the possibilities to circumvent these limitations due to the ultrathin nature of metasurfaces.[10,11,12,13,14,15,16]
In the following, we demonstrate the electromagnetic properties of the proposed metasurface, including the topological transition of equal-frequency contours (EFCs) in the wave vector space, frequency-dependent spatial localization, nondiffraction propagation, negative refraction and dispersion-dependent spin-momentum locking of spoof spin of the surface plasmon polariton (SPPs)

Summary

Introduction

Metamaterial is an artificial material with subwavelength unit cells that exhibit unusual properties that are never found in nature.[1]. While at terahertz and infrared frequencies, it has been theoretically predicted that uniform graphene nanostrips may provide a hyperbolic uniaxial conductivity.[14]

Methods

Results

Conclusion