Coupling between light and matter has many infusive physical effects and potential applications. Large Rabi splitting energy is achieved in many plasmonic nanostructures; however, these noble metallic materials generally suffer from a high level of Joule heating losses at optical frequencies. As an alternative strategy, all‐dielectric materials for manipulating light at the subwavelength scale have attracted enormous interest. However, the understanding of the interactions between all‐dielectric nanostructures and molecular excitons remains limited to date. Here, the use of a germanium nanogroove as a new all‐dielectric metasurface building block is demonstrated for the Kerker effect between molecular excitons and nanocavities. A distinct dip in the backward scattering spectra is observed, indicating relatively strong light–matter interaction due to the cavity magnetic resonance mode in the grooves. Germanium with a large real part and nonnegligible imaginary part of the refractive index in the visible region provides magnetic field enhancement similar to that of other all‐dielectric nanostructures; this phenomenon is theoretically explained by simulating the magnetic field distribution in the grooves. These findings may help researchers to better understand the interactions between all‐dielectric nanostructures and molecular excitons and indicate that germanium nanogrooves can potentially be used as metasurface building blocks in nanophotonic devices.

中文翻译：

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激子和纳米腔之间的克尔效应的全介电超表面构件：锗纳米槽

光与物质之间的耦合具有许多有害的物理效应和潜在的应用。在许多等离激元纳米结构中可实现大的拉比分裂能。然而，这些贵金属材料通常在光频率下遭受高的焦耳热损耗。作为一种替代策略，用于在亚波长范围内操纵光的全介电材料引起了极大的兴趣。但是，迄今为止，对全介电纳米结构和分子激子之间相互作用的理解仍然很有限。在这里，已证明了使用锗纳米沟槽作为新型的全介电超表面的构建单元，可用于分子激子和纳米腔之间的克尔效应。在后向散射光谱中观察到明显的下降，表明由于凹槽中的腔体磁共振模式，光与物质之间的相互作用相对较强。锗在可见光区域的折射率具有很大的实部和虚部不可忽略，与其他全电介质纳米结构相似，其磁场增强作用也很明显。理论上通过模拟凹槽中的磁场分布可以解释这种现象。这些发现可能有助于研究人员更好地理解全介电纳米结构与分子激子之间的相互作用，并表明锗纳米槽可潜在地用作纳米光子器件中的超表面构件。锗在可见光区域的折射率具有很大的实部和虚部不可忽略，与其他全电介质纳米结构相似，其磁场增强作用也很明显。理论上通过模拟凹槽中的磁场分布可以解释这种现象。这些发现可能有助于研究人员更好地理解全介电纳米结构与分子激子之间的相互作用，并表明锗纳米槽可潜在地用作纳米光子器件中的超表面构件。锗在可见光区域的折射率具有很大的实部和虚部不可忽略，与其他全电介质纳米结构相似，其磁场增强作用也很明显。理论上通过模拟凹槽中的磁场分布可以解释这种现象。这些发现可能有助于研究人员更好地理解全介电纳米结构与分子激子之间的相互作用，并表明锗纳米槽可潜在地用作纳米光子器件中的超表面构件。