Exciting Pseudospin-Dependent Edge States in Plasmonic Metasurfaces

Matthew Proctor, Richard V. Craster, Stefan A. Maier, Vincenzo Giannini, Paloma A. Huidobro

Research output: Contribution to journalArticleResearchpeer-review

37 Citations (Scopus)

Abstract

We study a plasmonic metasurface that supports pseudospin-dependent edge states confined at a subwavelength scale, considering full electrodynamic interactions including retardation and radiative effects. The spatial symmetry of the lattice of plasmonic nanoparticles gives rise to edge states with properties reminiscent of the quantum spin Hall effect in topological insulators. However, unlike the spin-momentum locking characteristic of topological insulators, these modes are not purely unidirectional and their propagation properties can be understood by analyzing the spin angular momentum of the electromagnetic field, which is inhomogeneous in the plane of the lattice. The local sign of the spin angular momentum determines the propagation direction of the mode under a near-field excitation source. We also study the optical response under far-field excitation and discuss in detail the effects of radiation and retardation.

Original languageEnglish
Pages (from-to)2985-2995
Number of pages11
JournalACS Photonics
Volume6
Issue number11
DOIs
Publication statusPublished - 20 Nov 2019
Externally publishedYes

Keywords

  • edge states
  • metasurface
  • nanoparticle array
  • plasmonics
  • pseudospin
  • topological photonics

Cite this