Beyond the extensively studied microcavity polaritons, which are coupled modes of semiconductor excitons and microcavity photons, nearly 2D semiconductors placed in a suitable environment can support spatially localized exciton–polariton modes. We demonstrate theoretically that two distinct types of such modes can exist in a photonic crystal with an embedded transition metal dichalcogenide (TMD) monolayer and derive an equation that determines their dispersion relations. The localized modes of two types occur in the zeroth- and first-order stop bands of the crystal and have substantially different properties. The latter type of localized modes, which appear inside the light cone, can be described as a result of coupling of the TMD exciton and an optical Tamm state of the TMD-intercalated photonic crystal. We suggest an experiment for detecting these modes and simulate it numerically.

中文翻译：

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由过渡金属二硫属化物单层插入的光子晶体中的局域极化子态

除了广泛研究的微腔极化子，这是半导体激子和微腔光子的耦合模式，放置在合适环境中的近二维半导体可以支持空间局部激子 - 极化模式。我们从理论上证明了两种不同类型的这种模式可以存在于具有嵌入的过渡金属二硫属化物 (TMD) 单层的光子晶体中，并推导出确定它们的色散关系的方程。两种类型的局域模式出现在晶体的零阶和一阶阻带中，并且具有明显不同的特性。后一种局域模式出现在光锥内部，可以描述为 TMD 激子与 TMD 插层光子晶体的光学 Tamm 状态耦合的结果。