Topological collective plasmons in bipartite chains of metallic nanoparticles

Abstract

We study a bipartite linear chain constituted by spherical metallic nanoparticles, where each nanoparticle supports a localized surface plasmon. The near-field dipolar interaction between the localized surface plasmons gives rise to collective plasmons, which are extended over the whole nanoparticle array. We derive analytically the spectrum and the eigenstates of the collective plasmonic excitations. At the edge of the Brillouin zone, the spectrum is of a pseudorelativistic nature similar to that present in the electronic band structure of polyacetylene. We find the effective Dirac Hamiltonian for the collective plasmons and show that the corresponding spinor eigenstates represent one-dimensional Dirac-like massive bosonic excitations. Therefore, the plasmonic lattice exhibits similar effects to those found for electrons in one-dimensional Dirac materials, such as the ability for transmission with highly suppressed backscattering due to Klein tunneling. We also show that the system is governed by a nontrivial Zak phase, which predicts the manifestation of edge states in the chain. When two dimerized chains with different topological phases are connected, we find the appearance of the bosonic version of a Jackiw-Rebbi midgap state. We further investigate the radiative and nonradiative lifetimes of the collective plasmonic excitations and comment on the challenges for experimental realization of the topological effects found theoretically.

16 pages, 10 figures. v2: published version

References in corpus (14)

• The electronic properties of graphene
• Chiral tunneling and the Klein paradox in graphene
• Topological Photonics
• Topological Field Theory of Time-Reversal Invariant Insulators
• How to face the loss in plasmonics and metamaterials
• Selective enhancement of topologically induced interface states in a dielectric resonator chain
• Propagation of Surface Plasmons in Ordered and Disordered Chains of Metal Nanospheres
• Dirac-like plasmons in honeycomb lattices of metallic nanoparticles
• Surface plasmon in metallic nanoparticles: renormalization effects due to electron-hole excitations
• Chirality of topological gap solitons in bosonic dimer chains
• Lifetime of the first and second collective excitations in metallic nanoparticles
• Nonradiative limitations to plasmon propagation in chains of metallic nanoparticles
• Tunable plasmon polaritons in arrays of interacting metallic nanoparticles
• Dirac plasmons in bipartite lattices of metallic nanoparticles

Cited by in corpus (5)

• Topological phases in the non-Hermitian Su-Schrieffer-Heeger model
• A perspective on topological nanophotonics: current status and future challenges
• Localization of massless Dirac particles via spatial modulations of the Fermi velocity
• Retardation effects on the dispersion and propagation of plasmons in metallic nanoparticle chains
• Plasmonic edge states: an electrostatic eigenmode description