Manipulating Topological Valley Modes in Plasmonic Metasurfaces

TL;DR

This paper explores how topological principles can be applied to plasmonic metasurfaces to create robust, subwavelength light modes with potential applications in guiding, filtering, and splitting light at the nanoscale.

Contribution

It systematically analyzes topological valley states in various nanoparticle lattice geometries, revealing new effects like robust guiding and dual-band phenomena in plasmonics.

Findings

Identification of all valley states in hexagonal and square lattices.

Demonstration of robust mode guiding and filtering.

Discovery of dual-band effects in plasmonic metasurfaces.

Abstract

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