Nonsymmorphic symmetry-protected topological modes in plasmonic nanoribbon lattices

Yong Liang Zhang, Raymond P.H. Wu, Anshuman Kumar, Tieyan Si, Kin Hung Fung (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

Using a dynamic eigenresponse theory, we study the topological edge plasmon modes in dispersive plasmonic lattices constructed by unit cells of multiple nanoribbons. In dipole approximation, the bulk-edge correspondence in the lattices made of dimerized unit cell and one of its square-root daughter with nonsymmorphic symmetry are demonstrated. Calculations with consideration of dynamic long-range effects and retardation are compared to those given by nearest-neighbor approximations. It is shown that nonsymmorphic symmetry opens up two symmetric gaps where versatile topological edge plasmon modes are found. Unprecedented spectral shifts of the edge states with respect to the zero modes due to long-range coupling are found. The proposed ribbon structure is favorable to electrical gating and thus could serve as an on-chip platform for electrically controllable subwavelength edge states at optical wavelengths. Our eigenresponse approach provides a powerful tool for the radiative topological mode analysis in strongly coupled plasmonic lattices.
Original languageEnglish
Article number144203
JournalPhysical Review B
Volume97
Issue number14
DOIs
Publication statusPublished - 20 Apr 2018

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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