Embedded eigenstates are nonradiative modes of an open structure with momentum compatible with radiation, yet characterized by unboundedly large Q factors. Traditionally, these states originate from total destructive interference of radiation from two or more nonorthogonal modes in periodic structures. In this work, we demonstrate a class of embedded eigenstates based on Berreman modes in epsilon-near-zero layered materials and propose realistic silicon carbide structures that support high-Q ($-{10}^3$) resonances based on these principles. The proposed structures demonstrate strong absorption in a narrow spectral and angular range, giving rise to quasicoherent and highly directive thermal emission.

中文翻译：

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Berreman嵌入式本征态用于窄带吸收和热发射

嵌入的本征态是开放结构的非辐射模式，其动量与辐射兼容，但具有无限大的Q因子。传统上，这些状态源自周期性结构中两个或多个非正交模式的辐射的总破坏性干涉。在这项工作中，我们展示了一种在ε接近零的层状材料中基于Berreman模式的嵌入式本征态，并提出了支持高Q（$-{10}^3$）基于这些原理的共振。所提出的结构在狭窄的光谱和角度范围内显示出强大的吸收能力，从而产生了准相干和高度定向的热发射。