To achieve large-scale quantum communication, chip based integration is the key direction. After more than 6 years of technological breakthroughs, the team led by Peking University professors Wang Jianwei, Gong Qihuang, and researcher Chang Lin has developed two core chips, successfully building the world's first large-scale quantum key distribution network based on integrated optical quantum chips - the "Nameless Quantum Core Network". The relevant paper was published in Nature on the 12th Beijing time. Dual field quantum key distribution (TF-QKD) combines the security of measurement equipment independence with the advantage of ultra long distance transmission. Chinese scientists have achieved point-to-point key distribution in fiber optics at the level of thousands of kilometers. However, the implementation of TF-QKD highly relies on stable single photon interference between remote independent laser sources, which poses extremely high requirements for source noise suppression and high-precision locking and tracking of global phase. Most existing experiments are still based on bulk or discrete fiber optic devices, and most are point-to-point systems for two users. Quantum key distribution chip (QKD chip) is one of the important paths to achieve miniaturization, device practicality, and network scaling of quantum communication systems. The research team has developed two chips this time. One is a server-side optical microcavity comb light source chip that can generate ultra-low noise coherent light sources, providing a unified "frequency reference" for the entire network and ensuring the synchronization of communication for all users; The other is a quantum key transmission chip for the user side, which integrates all key functions such as lasers, modulators, key encoding and decoding, achieving full functional integration. On this basis, the research team constructed an "unnamed quantum core network". This network solves the pain points of few users, limited distance, and complex equipment in previous quantum communication networks. It can support 20 chip users to communicate in parallel at the same time, and the communication distance between any two users can reach 370 kilometers. It breaks the technical boundary of relay free communication and has a networking capacity of 3700 kilometers, achieving a breakthrough in multi-user, long-distance quantum communication. This breakthrough has taken a crucial step towards the practical and scalable development of quantum communication, with relevant technical indicators reaching the international leading level. It is worth mentioning that the team's photonic quantum chips have high uniformity and yield in wafer level fabrication, and are expected to achieve low-cost mass production, which is of crucial significance for building large-scale quantum communication networks. The reviewers of the journal Nature believe that this is a major breakthrough in the field of quantum chips and quantum networks, and the quantum chip network it demonstrates has significant scalability, which will have an important impact on the field of quantum communication. Wang Jianwei stated that this is the first international demonstration of a quantum key distribution network based on photonic quantum chips in over 20 years. The team will continue to promote the integration research of quantum communication chip networks and quantum computing chips, laying the foundation for building an integrated and practical quantum information technology system. (New Society)