发表机构
Skolkovo Institute of Science and Technology; Osipyan Institute of Solid State Physics RAS（斯科尔科沃科学技术研究所; 俄罗斯科学院奥西皮扬固体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究数值模拟了周期倍增Si3N4光子晶体与MoSe2单层的混合结构，通过hBN厚度调谐将拉比分裂增强至8.5 meV，并控制极化激元色散，为强耦合平台提供新方案。
AI 中文摘要
我们数值研究了由周期倍增的Si3N4光子晶体平板和hBN封装的MoSe2单层构成的混合结构中的激子-光子耦合。周期倍增将准导模折叠进光锥内，并产生光谱分离的光子分支，其辐射特性由倍增单元胞的对称性控制，从而在正入射下产生一个亮态和一个连续谱中的束缚态（BIC）类模式。然后，我们利用hBN厚度作为垂直场分布的独立调谐参数。增加hBN厚度会将共振场重新分布到MoSe2单层，并将拉比分裂从约3-4 meV增强至8.5 meV，对应耦合强度从约1.5-1.7 meV增加到4.3-4.4 meV。亮态与BIC类构型的比较表明，品质因子主要决定辐射可见性和线宽，而耦合强度主要由单层处的场振幅决定。我们进一步证明，hBN层控制有限动量下折叠TE类模式的杂化，导致额外的光子带隙，其大小可通过hBN厚度调谐，并在hBN厚度约为113 nm时闭合。在混合结构中，我们观察到有限动量的激子-极化激元态，根据hBN厚度，这些态要么通过与孤立光子分支耦合形成，要么通过与两个近简并光子模式耦合形成。这些结果将周期倍增的光子晶体平板确定为一种灵活平台，用于控制基于过渡金属二硫化物单层的混合结构中的辐射耦合、激子-光子重叠和极化激元色散。
英文摘要
We numerically study exciton-photon coupling in a hybrid structure composed of a period-doubled Si3N4 photonic crystal slab and an hBN-encapsulated MoSe2 monolayer. Period doubling folds quasi-guided modes into the light cone and produces spectrally separated photonic branches whose radiative character is controlled by the symmetry of the doubled unit cell, resulting in one bright and one bound state in the continuum (BIC)-like mode at normal incidence. We then use the hBN thickness as an independent tuning parameter for the vertical field profile. Increasing the hBN thickness redistributes the resonant field toward the MoSe2 monolayer and enhances the Rabi splitting from about 3-4 meV to 8.5 meV, corresponding to an increase in the coupling strength from approximately 1.5-1.7 meV to 4.3-4.4 meV. Comparison between bright and BIC-like configurations shows that the quality factor primarily determines radiative visibility and linewidth, whereas the coupling strength is mainly governed by the field amplitude at the monolayer. We further show that the hBN layer controls the hybridization of folded TE-like modes at finite momentum, leading to an additional photonic gap whose size can be tuned by the hBN thickness and closes at an hBN thickness of approximately 113 nm. In the hybrid structure, we observe finite-momentum exciton-polariton states that, depending on the hBN thickness, form either through coupling to an isolated photonic branch or through coupling to two nearly degenerate photonic modes. These results identify period-doubled photonic crystal slabs as a flexible platform for controlling radiative coupling, exciton-photon overlap, and polariton dispersion in hybrid structures based on transition-metal dichalcogenide monolayers.
