  Graphene hybrids, made of thin insulators, graphene, and metals can support
propagating acoustic plasmons (AGPs). The metal screening modifies the
dispersion relation of usual graphene plasmons leading to slowly propagating
plasmons, with record confinement of electromagnetic radiation. Here, we show
that a graphene monolayer, covered by a thin dielectric material and an array
of metallic nanorods can be used as a robust platform to emulate the
Su-Schrieffer-Heeger model. We calculate the Zak's phase of the different
plasmonic bands to characterise their topology. The system shows bulk-edge
correspondence: strongly localized interface states are generated in the domain
walls separating arrays in different topological phases. We find signatures of
the nontrivial phase which can directly be probed by far-field mid-IR
radiation, hence allowing a direct experimental confirmation of graphene
topological plasmons. The robust field enhancement, highly localized nature of
the interface states, and their gate-tuned frequencies expand the capabilities
of AGP-based devices.
