Light–matter interactions in quantum nanophotonic devices

Nanophotonics offers opportunities for engineering and exploiting the quantum properties of light by integrating quantum emitters into nanostructures, and offering reliable paths to quantum technology applications such as sources of quantum light or new quantum simulators, among many others. In this Review, we discuss common nanophotonic platforms for studying light–matter interactions, explaining their strengths and experimental state-of-the-art. Each platform works at a different interaction regime: from standard cavity quantum electrodynamics (QED) setups to unique quantum nanophotonic devices, such as chiral and non-chiral waveguide QED experiments. When several quantum emitters are integrated into nanophotonic systems, collective interactions emerge, enabling miniaturized, versatile and fast-operating quantum devices. We conclude with a perspective on the near-term opportunities offered by nanophotonics in the context of quantum technologies.