AI 中文总结
该研究采用量子多体理论揭示等离激元-激子耦合体系中极化激元介导的拉曼散射机制，推导了拉曼强度与增强因子的解析表达式，解释了极化激元分支线宽不对称性，建立了耦合体系动力学演化的通用框架。
AI 中文摘要
一系列实验结果表明，等离激元-激子耦合体系中存在独特的拉曼响应，不同声子模式的拉曼散射增强效应存在差异。我们采用量子多体理论描述该拉曼散射的微观动力学过程：与涉及电子-声子相互作用的常规拉曼散射不同，等离激元-激子耦合体系中的该过程以声子与等离激元-激子极化激元（由等离激元与激子耦合形成，作为中间态）之间的非弹性散射为特征。我们推导了不同声子模式的拉曼强度与增强因子的解析表达式，其与实验数据吻合度极高。此外，实验拟合显示上下极化激元分支的线宽存在显著差异，我们对此提供了全面的理论解释。基于线性响应理论，我们提出了等离激元-激子极化激元形成的微观机制，可实现其色散关系与线宽的解析计算，该方法自然解释了观测到的上下极化激元分支线宽的显著不对称性。通过在量子层面表征极化激元-声子散射过程，我们揭示了驱动极化激元增强拉曼散射的基本物理机制，为描述耦合体系的动力学演化建立了通用框架，为探索等离激元与其他准粒子的相互作用提供了通用范式。
英文摘要
A series of experimental results demonstrate a distinctive Raman response in plasmon-exciton coupled systems. The enhancement of Raman scattering varies for different phonon modes. We describe the microscopic dynamical process of this Raman scattering using quantum many-body theory. Unlike conventional Raman scattering involving electron-phonon interactions, the process in plasmon-exciton coupled systems is characterized by inelastic scattering between phonons and plasmon-exciton polaritons-formed through the coupling of plasmons and excitons-acting as intermediate states. We derive analytical expressions for the Raman intensity and enhancement factors for various phonon modes, which show excellent agreement with experimental data. Furthermore, experimental fittings indicate a substantial disparity in the linewidths of the upper and lower polariton branches, for which we provide a comprehensive theoretical explanation. Based on linear response theory, we propose a microscopic mechanism for the formation of plasmon-exciton polaritons, enabling the analytical calculation of their dispersions and linewidths. This approach naturally accounts for the significantly asymmetry observed in the linewidths of the upper and lower polariton branches. By characterizing the polariton-phonon scattering process at the quantum level, we reveal the fundamental physical mechanism driving polariton-enhanced Raman scattering. Our work establishes a universal framework for describing the dynamical evolution of coupled systems, providing a versatile paradigm for exploring the interactions between plasmons and other quasiparticles.
