High-index dielectric nanoantennas, which provide an interplay between electric and magnetic modes, have been widely used as building blocks for a variety of devices and metasurfaces, both in linear and nonlinear regimes. Here, we investigate hybrid metal-semiconductor nanoantennas, consisting of a multimode silicon nanopillar core coated with a gold layer, that offer an enhanced degree of control over the mode selection and confinement, and emission of light on the nanoscale exploiting high-order electric and magnetic resonances. Cathodoluminescence spectra revealed a multitude of resonant modes supported by the nanoantennas due to hybridization of the Mie resonances of the core and the plasmonic resonances of the shell. Eigenmode analysis revealed the modes that exhibit enhanced field localization at the gold interface, together with high confinement within the nanopillar volume. Consequently, this architecture provides a flexible means of engineering nanoscale components with tailored optical modes and field confinement for a plethora of applications, including sensing, hot-electron photodetection and nanophotonics with cylindrical vector beams.

中文翻译：

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用于定制纳米级光学限制的多模混合金硅纳米天线

高折射率介电纳米天线可提供电模式和磁模式之间的相互作用，已广泛用作线性和非线性状态下各种设备和超表面的构建块。在这里，我们研究了混合金属-半导体纳米天线，由涂有金层的多模硅纳米柱核心组成，它利用高阶电和纳米尺度的光发射，提供了对模式选择和限制以及纳米级光发射的增强程度的控制。磁共振。阴极发光光谱揭示了由于核的米氏共振和壳的等离子体共振的杂化而由纳米天线支持的多种共振模式。本征模分析揭示了在金界面处表现出增强的场定位以及纳米柱体积内的高限制的模式。因此，这种架构提供了一种灵活的方法来设计纳米级组件，具有定制的光学模式和场限制，适用于多种应用，包括传感、热电子光电探测和圆柱形矢量光束的纳米光子学。