Realizing an Entanglement-Based Multiuser Quantum Network with Integrated Photonics

Fully connected quantum networks have been realized with bulk nonlinear crystals and passive filters, but this traditional optical platform limits a network's scalability in terms of photon-pair number and brightness, compatibility with quantum memory, and cost effectiveness. The authors address all of those challenges by employing an integrated SiN microring resonator to generate energy-time-entangled quantum frequency microcombs with a wide frequency span and narrow bandwidth modes. Photon pairs are selected and distributed to form a fully and simultaneously connected multiuser quantum network, paving the way to turnkey solutions for large entanglement-based quantum networks.