Cortese Erika, De Liberato Simone
School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom.
J Chem Phys. 2022 Feb 28;156(8):084106. doi: 10.1063/5.0077950.
In this paper, we perform the exact diagonalization of a light-matter strongly coupled system taking into account arbitrary losses via both energy dissipation in the optically active material and photon escape out of the resonator. This allows us to naturally treat the cases of couplings with structured reservoirs, which can strongly impact the polaritonic response via frequency-dependent losses or discrete-to-continuum strong coupling. We discuss the emergent gauge freedom of the resulting theory and provide analytical expressions for all the gauge-invariant observables in both the Power-Zienau-Woolley and the Coulomb representations. In order to exemplify the results, the theory is finally specialized to two specific cases. In the first one, both light and matter resonances are characterized by Lorentzian linewidths, and in the second one, a fixed absorption band is also present. The analytical expressions derived in this paper can be used to predict, fit, and interpret results from polaritonic experiments with arbitrary values of the light-matter coupling and with losses of arbitrary intensity and spectral shape in both the light and matter channels. A Matlab code implementing our results is provided.
在本文中，我们通过光学活性材料中的能量耗散以及光子从谐振器中逸出这两种方式，对考虑了任意损耗的光与物质强耦合系统进行精确对角化。这使我们能够自然地处理与结构化库耦合的情况，这种耦合可通过频率相关损耗或离散到连续的强耦合对极化激元响应产生强烈影响。我们讨论了所得理论中出现的规范自由度，并给出了在Power-Zienau-Woolley和库仑表示中所有规范不变可观测量的解析表达式。为了举例说明结果，该理论最终专门针对两种特定情况。在第一种情况中，光和物质共振均由洛伦兹线宽表征，在第二种情况中，还存在一个固定的吸收带。本文推导的解析表达式可用于预测、拟合和解释极化激元实验结果，这些实验具有任意值的光与物质耦合以及光和物质通道中任意强度和光谱形状的损耗。我们提供了一个实现我们结果的Matlab代码。
