Many quantum technologies require on-demand quantum sources, such as single-photon sources that should emit one and only one photon at a certain time. Traditionally, single photons have been generated by attenuating laser pulses or spontaneous parametric down-conversion, which usually require bulky configurations with generated single photons being inherently probabilistic. In contrast, spontaneous emission from solid-state quantum emitters (QEs) allows for deterministic single-photon generation. Additionally, quantum state engineering, the cornerstone of quantum photonic technologies, is mainly performed with a sequence of discrete optical components, restricting the potential of on-chip quantum integration.
Optical plasmon-polariton metasurfaces, i.e., ultrathin arrays of engineered meta-atoms, have attracted increasing attention due to their unprecedented capabilities of molding classical light and thus replacing bulky optical components with ultrathin planar elements. Besides controlling classical light, metasurfaces have the potential to emerge as essential components for quantum optics at the single-photon level. Plasmon-polariton metasurfaces, when employed in the generation of non-classical light, allow us to generate single photons carrying arbitrary spin and orbital angular momenta, thereby multiplying quantum-information capacities. The generic configuration involves QEs (solid-state defects, quantum dots, excitons in TMDs) non-radiatively coupled to polariton modes, which interact with engineered optical metasurfaces to produce well-collimated single-photon streams in the far field. The same platform also enables the natural integration of QEs in nanophotonic environments for Purcell enhancement of spontaneous emission rates, potentially beyond ambient decoherence rates, resulting eventually in the room-temperature generation of indistinguishable photons.
Optical plasmon-polariton metasurfaces, i.e., ultrathin arrays of engineered meta-atoms, have attracted increasing attention due to their unprecedented capabilities of molding classical light and thus replacing bulky optical components with ultrathin planar elements. Besides controlling classical light, metasurfaces have the potential to emerge as essential components for quantum optics at the single-photon level. Plasmon-polariton metasurfaces, when employed in the generation of non-classical light, allow us to generate single photons carrying arbitrary spin and orbital angular momenta, thereby multiplying quantum-information capacities. The generic configuration involves QEs (solid-state defects, quantum dots, excitons in TMDs) non-radiatively coupled to polariton modes, which interact with engineered optical metasurfaces to produce well-collimated single-photon streams in the far field. The same platform also enables the natural integration of QEs in nanophotonic environments for Purcell enhancement of spontaneous emission rates, potentially beyond ambient decoherence rates, resulting eventually in the room-temperature generation of indistinguishable photons.