连续谱中极化子束缚态与二维辐射激子的共存
Coexistence of polariton bound states in the continuum and 2D radiative excitons
- Nanyang Technological University（南洋理工大学）
- Università di Pavia（帕维亚大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究提出纳入激子辐射损耗的非厄米Hopfield形式论，证实存在k=0极化子BICs，为辐射激子与极化子BICs提供统一微观框架，可用于设计耦合二维激子材料的光子晶体平台。
AI中文摘要：
连续谱中的束缚态（BICs）可实现光学模式，即便处于辐射连续谱内，其辐射寿命理论上为无限长。嵌入二维（2D）光学活性激发的周期性图案化平面波导中的辐射-物质相互作用，可通过对角化非厄米算符（即Hopfield矩阵）进行量子力学描述，该矩阵可纳入独立的光子与激子损耗以形成极化子态。然而，由于二维激子在光锥内会经历与波矢相关的本征辐射衰减，Hopfield形式论能否在保留极化子BICs的同时一致地解释该过程仍是未解决的问题。本文表明，纳入激子辐射损耗的非厄米Hopfield形式论可正确捕获具有发散辐射寿命的真实k=0极化子BICs的存在。该理论为辐射激子与极化子BICs提供了统一的微观框架，也是设计耦合量子阱、过渡金属二硫化物及其他二维激子材料的光子晶体平台的高效预测工具。
英文摘要：
Bound states in the continuum (BICs) enable optical modes with ideally infinite radiative lifetimes despite lying within the radiation continuum. Radiation-matter interaction in periodically patterned planar waveguides embedding two-dimensional (2D) optically active excitations can be described quantum mechanically by diagonalizing a non-Hermitian operator, known as the Hopfield matrix, which can be generalized to incorporate independent photonic and excitonic losses into the polaritonic states. However, since 2D excitons undergo intrinsic wavevector-dependent radiative decay within the light cone, whether the Hopfield formalism can consistently account for this process while preserving polariton BICs has remained an open question. Here we show that a non-Hermitian Hopfield formalism incorporating excitonic radiative losses correctly captures the existence of genuine $k=0$ polariton BICs with diverging radiative lifetimes. The theory provides a unified microscopic framework for radiative excitons and polariton BICs, and an efficient predictive tool for designing photonic-crystal platforms coupled to quantum wells, transition-metal dichalcogenides, and other 2D excitonic materials.
