Type-I hyperbolic metasurfaces for highly-squeezed designer polaritons with negative group velocity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31043595.
- Also identified by DOI 10.1038/s41467-019-10027-0 and PMC identifier 6494850.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Hyperbolic polaritons in van der Waals materials and metamaterial heterostructures provide unprecedented control over light-matter interaction at extreme nanoscales. Here we propose a concept of type-I hyperbolic metasurface supporting highly-squeezed magnetic designer polaritons, which act as magnetic analogs of hyperbolic polaritons in the hexagonal boron nitride (h-BN) in the first Reststrahlen band. Compared with the natural h-BN, the size and spacing of the metasurface unit cell can be readily engineered, allowing for manipulating designer polaritons in frequency and space with greater flexibility. Microwave experimental measurements display a cone-like dispersion in momentum space, exhibiting an effective refractive index up to 60 and a group velocity down to c/400. Tailoring the metasurface, we demonstrate an ultra-compact integrated designer polariton circuit including high-transmission 90° sharp bending waveguides and waveguide splitters. The present metasurface could serve as a platform for polaritonics, and find applications in waveguiding, terahertz sensing, subdiffraction focusing/imaging, low-threshold terahertz Cherenkov radiation, and wireless energy transfer.