Although plasmonics and high refractive index photonics have experienced very fast growth thanks to classical physics concepts, there is an increasing interest in harnessing quantum physics concepts for further pushing the frontiers of these fields. In this context, this perspective highlights the importance of some quantum nanostructures for building nanomaterials and metamaterials with enhanced plasmonic and high refractive index properties. Two types of nanostructures displaying quantum properties are considered: (a) quantum confined nanostructures consisting of noble metals or standard semiconductors, (b) nanostructures built from alternative materials whose dielectric function and optical properties are driven by (possibly tailored) giant interband electronic transitions. A special emphasis is made on the potential of this latter type of nanostructures for achieving outstanding effects for applications, such as ultrabroadband light harvesting, giant refractive index, coupling between dielectric, low-loss plasmonic and magnetic properties, compositionally or externally tuneable optical response. Possible future developments to the field are discussed.

尽管由于经典物理学的概念，等离激元学和高折射率光子学经历了非常快速的发展，但人们对利用量子物理学概念来进一步推动这些领域的前沿领域的兴趣日益浓厚。在这种情况下，这种观点突出了某些量子纳米结构对于构建具有增强的等离子体和高折射率特性的纳米材料和超材料的重要性。考虑了两种显示量子特性的纳米结构：（a）由贵金属或标准半导体组成的量子受限纳米结构；（b）由介电功能和光学特性由（可能是定制的）巨大的带间电子跃迁驱动的替代材料构成的纳米结构。特别强调了后一种类型的纳米结构在实现卓越应用效果方面的潜力，例如超宽带光收集，巨大的折射率，介电之间的耦合，低损耗等离子体和磁性之间的耦合，组成上或外部可调的光学响应。讨论了该领域可能的未来发展。