Exploitation of strong light-matter interactions in plasmonic systems is vital for both fundamental studies and the development of new applications, which enables exceptional physical phenomena and promotes potential applications in nanophotonics, information communication, and quantum information processing. Here, we present an analytic model of the interaction between localized surface plasmon resonances and excitons, where a semiclassical method is utilized. Two kinds of metal nanoparticles (nanosphere and nanoellipsoid) are considered in our study. We derive the relations between the plasmon-exciton coupling strength and the geometry and material parameters of the coupled systems when the nanoparticles are put in an excitonic medium, which give an important guide to achieve strong plasmon-exciton coupling. Rabi splittings and anticrossing behavior are also demonstrated in the calculated extinction spectra. Furthermore, we propose an analytic model to describe the strong coupling between excitons and plasmon in a core-shell nanorod structure which is widely used in experiments. Our study provides a simple yet rigorous prescription to both analyze and design plexcitonic systems aiming at strong light-matter interactions.

中文翻译：

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等离激元-激子相互作用从弱到强耦合机制的半经典模型


利用等离子体系统中强光与物质的相互作用对于基础研究和新应用的开发都至关重要，它可以实现特殊的物理现象并促进纳米光子学、信息通信和量子信息处理中的潜在应用。在这里，我们提出了局域表面等离子体共振和激子之间相互作用的分析模型，其中使用了半经典方法。我们的研究考虑了两种金属纳米颗粒（纳米球和纳米椭球）。我们推导了纳米颗粒置于激子介质中时等离激元-激子耦合强度与耦合系统的几何形状和材料参数之间的关系，这为实现强等离激元-激子耦合提供了重要指导。计算的消光光谱也证明了拉比分裂和反交叉行为。此外，我们提出了一种解析模型来描述核壳纳米棒结构中激子和等离子体之间的强耦合，该结构在实验中广泛使用。我们的研究为分析和设计旨在强光与物质相互作用的复合系统提供了一个简单而严格的方案。