Plasmonic hybridization in complex nanostructures is
of fundamental
interest in multiple fields, such as chemistry, physics, materials
science, and biology. In this manuscript, we compared the similarities
of the building block of a multipolar monomer resonator (M
long,l=2) or an antibonding mode of a dimer (M
half,l=1–M
half,l=1)
of equivalent overall length in coupled plasmonic systems. First,
we performed numerical simulations to calculate the far-field resonances,
near-field profiles, and angular radiation profiles of asymmetric
coupled Au NR di-block (M
short,l=1–M
long,l=2) and tri-block (M
short,l=1–M
half,l=1–M
half,l=1) structures. Then, we studied the “gap
separation” between a building block of M
long,l=2 or M
half,l=1–M
half,l=1 and a dipole of M
short,l=1, and the change of strength of the plasmonic hybridization
due to the “gap effects” was discussed. Furthermore,
we studied the effect of dipole (M
short,l=1) on coupling. In particular, we investigated the carrier concentration
and damping velocity’s effect of dipole (M
short,l=1) on each mode of M′ω,γ,l=1–M
long,l=2 di-block or M′ω,γ,l=1–M
half,l=1–M
half,l=1 tri-block in terms of spectral shifts and near-field
enhancement factors. We believe that our work may contribute to the
fundamental understanding of plasmonic hybridization systems and pave
the path for new applications and opportunities in vast regimes of
plasmonic-photonic and nanoplasmonic.