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 nm³. This work may provide a useful reference value for further exploration of basic optical material research or the development of advanced quantum devices.

中文翻译：

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Ag@Au 空心纳米立方体/J-聚集体异质结构的吸收光谱强耦合

在室温下实现强光-物质相互作用对于研究量子光学和高级量子应用至关重要。在本文中，我们构建了由 Ag@Au 空心纳米立方体 (HNC) 和 J-聚集体组成的混合系统，以实现室温下的强等离子体激子相互作用。首先，通过改变 Ag@Au HNCs 的壳层厚度，我们调整了局域表面等离子体共振波长（λ _LSPR) 在激子峰 (575 nm) 附近。此外，杂化结构存在明显的反交叉曲线，Rabi分裂约为179 meV。最后，利用有限差分时域（FDTD）方法模拟了上述纳米结构的吸收光谱，结果与实验结果吻合较好。我们认为，实现强相互作用在于减小 Ag@Au HNCs 的局部表面等离子体模式的体积，约为 8645 nm ³。该工作可为进一步探索基础光学材料研究或开发先进量子器件提供有益的参考价值。