Plasmonic lattice nanostructures are of technological
interest
because of their capacity to manipulate light below the diffraction
limit. Here, we present a detailed study of dark and bright modes
in the visible and near-infrared energy regime of an inverted plasmonic
honeycomb lattice by a combination of Au+focused ion beam
lithography with nanometric resolution, optical and electron spectroscopy,
and finite-difference time-domain simulations. The lattice consists
of slits carved in a gold thin film, exhibiting hotspots and a set
of bright and dark modes. We proposed that some of the dark modes
detected by electron energy-loss spectroscopy are caused by antiferroelectric
arrangements of the slit polarizations with two times the size of
the hexagonal unit cell. The plasmonic resonances take place within
the 0.5–2 eV energy range, indicating that they could be suitable
for a synergistic coupling with excitons in two-dimensional transition
metal dichalcogenides materials or for designing nanoscale sensing
platforms based on near-field enhancement over a metallic surface.