Tunneling Plasmonics: Vacuum Rabi Oscillations in Carbon Nanotube Mediated Electromigrated Nanojunctions

The context of strong coupling has sparked extensive interest in both the photonics and solid-state physics communities, owing to its exquisite advantages in understanding intriguing phenomena, including but not limited to Bose-Einstein condensation, optical Stark and Hall effects, photon blockade effect, and extraordinary exciton conductance. This study reports on the theoretical realization of strong coupling in judiciously integrated semiconducting single-walled carbon nanotubes (SWCNTs) with metallic nanoelectrodes, reaching deeply into the Purcell regime through the interference between electrically driven radiative plasmons from the tunneling junctions and emitted excitons from an individual carbon nanotube. Quantitative analyses of both emission spectra and electroluminescence spectra in electromigrated tunnel junctions verified the formation of new energy levels, in particular, Rabi splitting of dipolar plasmonic moments (h Omega approximate to 127 meV) and the augmented Purcell effect (F-p = 105) at V-SD = 1.75 V. Furthermore, by taking advantage of the reasonably low mode volume (V-e = 3.44 X 10(-11) m(3) at lambda(cav), = 880 nm) of the electrically excited line shape, it is revealed that increasing the number of SWCNTs across the barrier gives rise to substantial enhancement in both Rabi splitting and the Purcell factor. This understanding paves a new approach toward the evolution of the strong coupling regime and boosted Purcell effect in electrically driven plasmonic junctions, which is insightful for photonic, plasmonic, and optoelectronic applications based on exciton polaritons and holds promise for structuring ultradense and on-chip instruments.