Strong Coupling of Ag@Au Hollow Nanocube/J-Aggregate Heterostructures by Absorption Spectra

Abstract

Achieving strong light−matter interactions at room temperature is critical for the study of quantum optics and advanced quantum applications. In this paper, we constructed a hybrid system composed of Ag@Au hollow nanocubes (HNCs) and J-aggregates to realize the strong plasmon−exciton interaction at room temperature. First, by changing the shell thickness of Ag@ Au HNCs, we tuned the localized surface plasmon resonance wavelength (λ LSPR ) near the exciton peak (575 nm). Furthermore, there is an obvious anticrossing curve in the hybrid structure, and the Rabi splitting is about 179 meV. Finally, the finite-difference time-domain (FDTD) method was utilized to simulate the absorption spectra of the above nanostructure, and the results matched well with the experimental results. We believe that achieving strong interactions lies in decreasing the volume of the local surface plasmon mode of the Ag@Au HNCs, which is approximately 8645 nm 3 . This work may provide a useful reference value for further exploration of basic optical material research or the development of advanced quantum devices.

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.…”

Trace detection of chiral J-aggregated molecules adsorbed on single Au nanorods

“…30–32 CD spectroscopy studies have been carried out on ensemble samples of J-aggregate-metal hybrid nanostructures. 23,25–28…”

“…[20][21][22] Recently, plasmon-exciton, or plexcitonic, hybridized chiral systems with resonance coupling have attracted renewed interest in the amplification of the optical activity of molecules. [23][24][25][26][27][28][29] Rabi splitting has been observed when absorbing molecules are in close vicinity of plasmonic nanostructures, and the excitonic absorption band of the molecules overlaps with the plasmonic band of the metal nanostructure. [30][31][32] CD spectroscopy studies have been carried out on ensemble samples of J-aggregate-metal hybrid nanostructures.…”

“…[30][31][32] CD spectroscopy studies have been carried out on ensemble samples of J-aggregate-metal hybrid nanostructures. 23,[25][26][27][28] Trace detection of chiral molecules requires state-of-the-art microscopic techniques at the single-particle or single-molecule level. Detection of a few macromolecules, such as proteins, has been successfully demonstrated on individual nanostructures.…”

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

“…Owing to a large number of oscillating charges, the plasmon nanocavity presents a highly efficient approach to field localization and engineering light–matter interactions at the nanoscale, which gives rise to the propelling transformative breakthroughs in a diverse set of areas, for example, extremely highly efficient emission such as plasmon-enhanced photoluminescence, plasmon-enhanced Raman scattering, and optical nonlinearity. − In particular, for plasmon coupling dimer metallic nanoparticles, huge field enhancements can be achieved in the gap between dimers; however, the resonant excitation of gap plasmons is a prerequisite. Previous studies have proved that the pronounced longitudinal bonding dipole plasmon (LBDP) modes of the dimer system may be influenced by the gap distance, gap morphology, gap area, gap facet, gap curvature, and even the size of a single nanoparticle. , Figure a,b shows the LBDP mode of the dimer gold nanodisk (the radius of the disk is fixed at R = 25 nm) evolving with the gap distance, and the inset shows the diagram of the dimer disk.…”