Multiuser all-optical quantum network based on metasurfaces

A crucial aspect of quantum information is the establishment of multiuser quantum networks, ensuring secure transmission of information among separated users. However, establishing a large-scale network remains a substantial challenge, requiring massive and compact Einstein-Podolsky-Rosen (EPR) entangled states. Here, we experimentally generate a 5 by 5 continuous variable (CV) EPR entanglement array using a metalens array. Moreover, on the basis of such a compact EPR entanglement array, we establish a five-user all-optical quantum state sharing (AOQSS) network with fidelity beating the corresponding classical limit, which is currently the largest AOQSS network in the CV regime. These results provide a promising platform for the generation of massive and compact EPR entangled states and the construction of large-scale all-optical multiuser quantum networks. Our compact approach for generating CV EPR entanglement based on metasurface opens up avenues for advanced quantum networks.