Independent engineering of individual plasmon modes in plasmonic dimers\n with conductive and capacitive coupling

Abstract

We revisit plasmonic modes in nanoparticle dimers with conductive or\ninsulating junction resulting in conductive or capacitive coupling. In our\nstudy which combines electron energy loss spectroscopy, optical spectroscopy,\nand numerical simulations, we show coexistence of strongly and weakly\nhybridized modes. While the properties of the former ones strongly depend on\nthe nature of the junction, the properties of the latter ones are nearly\nunaffected. This opens up a prospect for independent engineering of different\nplasmonic modes in a single plasmonic antenna. In addition, we show that\nBabinet's principle allows to engineer the near field of plasmonic modes\nindependent of their energy. Finally, we demonstrate that combined electron\nenergy loss imaging of a plasmonic antenna and its Babinet-complementary\ncounterpart allows to reconstruct the distribution of both electric and\nmagnetic near fields of localised plasmonic resonances supported by the antenna\nas well as charge and current antinodes of related charge oscillations.\n