Beijing: Chinese scientists have successfully constructed a 300-kilometre fully connected quantum secure direct communication (QSDC) network, marking a breakthrough in the field, the Beijing Academy of Quantum Information Sciences (BAQIS) said on Monday.
According to Emirates News Agency, the BAQIS team developed a multipump expandable fully connected QSDC network in noisy environments, designed to reduce complexity and increase the number of users while guaranteeing communication distance between users.
The quantum network serves as a platform for verifying the fundamental principles of quantum mechanics and realizing quantum communication and computation. This development is seen as a step towards real-world deployment of QSDC systems, with potential applications in sectors requiring ultra-secure communication, such as government operations and financial transactions.
A significant hurdle in QSDC development has been ensuring secure and reliable communication via quantum states, while the transmission d
istance and the number of users are two important factors that limit the realization of large-scale, scalable quantum communication networks. Existing quantum network construction techniques have struggled to address these challenges simultaneously.
“In our recent research, we propose a long-distance large-scale and scalable fully connected QSDC network, which employs a double-pumped structure and the introduction of extra noise to successfully realize QSDC over 300 kilometres between four users in the network in pairs,” the team stated.
By using multipump technology, the team can exhibit reduced complexity. This advancement ensures that the fidelity of the entangled states shared among users post-communication remained above 85 percent, thereby validating the scheme’s effectiveness and reliability over extended distances, according to the team.
The researchers reported three key technical milestones: overcoming traditional star-shaped network limitations to achieve scalable full connection, extending tran
smission distances to 300 kilometres through optimized entangled light source preparation, and establishing an error correction mechanism based on quantum state reconstruction to ensure stable multi-node communication.