Boosting Light–Matter Interaction in a Longitudinal Bonding Dipole Plasmon Hybrid Anapole System

Abstract

Achieving strong electromagnetic enhancement is critical for realizing strong light−matter coupling at the nanoscale. In this study, we constructed a hybrid anapole system composed of a nanohole silicon disk and a longitudinal bonding dipole plasmon mode-supported plasmonic dimer. Compared with the bare dimer plasmon, the hybrid system shows strong plasmonic resonance tuning ability, and its resonance peak can be tuned to the nearinfrared region only by adjusting the radius of the silicon disk. Meanwhile, the E-field enhancement in the gap region can exceed four orders of magnitude without sacrificing the quality factor of the system. Furthermore, it is demonstrated that the emitter's radiative decay rate enhancement in the hybrid system is much higher than that of a similar LBDP mode-supported plasmonic dimer nanodisk and the reported plasmonic nanocavity. In summary, our hybrid anapole systems combine the advantages of metal plasmonic nanodimers and conventional anapole mode-supported systems and avoid their disadvantages. This study provides a useful reference for the further exploration of single-photon emission sources, light harvesting, and other quantum nanophotonic applications.

Electromagnetically Induced Absorption Overcomes the Upper Limit of Light Absorption: Dipole–Dipole Coupling with Phase Retardation in Plasmonic-Dielectric Dimers

“…The scattered field created by the ED car and toroidal dipole resonances can interfere with each other in the far-field and create an anapole state when a certain condition is satisfied. 77 − 80 For our particles, their toroidal dipole resonances are weak, and we cannot see any anapoles ( Figure S2b , Supporting Information). Therefore, we can safely ignore the influence of the toroidal dipole resonances.…”

“…In addition to this spherical multipolar decomposition, Cartesian multipolar decomposition (CMD) has been widely recognized. − In CMD, the ED resonance of Mie theory is further decomposed to an ED resonance on a Cartesian basis (ED car ) and a toroidal dipole resonance. The scattered field created by the ED car and toroidal dipole resonances can interfere with each other in the far-field and create an anapole state when a certain condition is satisfied. − For our particles, their toroidal dipole resonances are weak, and we cannot see any anapoles (Figure S2b, Supporting Information). Therefore, we can safely ignore the influence of the toroidal dipole resonances.…”

Nanogap Plasmon Resonator: An Analytical Model

“…A good agreement was reached between our analytical model (at the excitation wavelength of 785 nm) and the simulation results obtained by Bozhevolnyi's group (see the black diamond in Figure 2b). Lastly, another comparison of our analytical model to the numerical simulations obtained by Li et al was made [64]. The nanostructure employed for these simulations was a dimer composed of gold disks with a radius of 25 nm and a gap in between of 3 nm.…”

Strong Coupling of Plasmonic Nanorods with a MoSe2 Monolayer in the Near-Infrared Shortwave Region

“…In the quantum mechanical mode, the coupling strength, which is determined as g = N μ e · E ∝ μ e N / V , (where N is the effective exciton number coherently contributing to the interaction with the cavity, μ e is exciton transition dipole moment, E is the vacuum field amplitude) is inversely proportional to the mode volume V . , To achieve a high coupling strength, a highly effective approach is to reduce the mode volume, V eff , for plasmonic nanocavities. Light can be confined to an ultrasmall volume, which promotes the light–matter interaction. − Recently, strong coupling has been achieved in different metallic nanostructures with small effective volumes, such as single hollow nanoparticles, gold nanobipyramids, nanorods, nanoprisms, nanocubes, and even the gaps between nanoparticles and mirrors. − However, the strong coupling regime has always been investigated in the optical spectrum, and research on coherent states in the near-infrared shortwave region (NIR-I) is limited. This is because tuning the plasmonic resonance peak to the NIR-I is difficult, while maintaining a small mode volume.…”