Manipulating topological valley modes in plasmonic metasurfaces

• Main Authors: Proctor Matthew, Huidobro Paloma A., Maier Stefan A., Craster Richard V., Makwana Mehul P.
• Format: Article
• Language: English
• Published: De Gruyter 2020-02-01
• Series: Nanophotonics
• Subjects: metal nanoparticles; plasmonic metasurface; topological nanophotonics; topological plasmonics; topological valley modes
• Online Access: http://www.degruyter.com/view/j/nanoph.2020.9.issue-3/nanoph-2019-0408/nanoph-2019-0408.xml?format=INT

Coupled light-matter modes supported by plasmonic metasurfaces can be combined with topological principles to yield subwavelength topological valley states of light. This study gives a systematic presentation of the topological valley states available for lattices of metallic nanoparticles (NPs): all possible lattices with hexagonal symmetry are considered as well as valley states emerging on a square lattice. Several unique effects that have yet to be explored in plasmonics are identified, such as robust guiding, filtering, and splitting of modes, as well as dual-band effects. These are demonstrated by means of scattering computations based on the coupled dipole method that encompass full electromagnetic interactions between NPs.