One of the main technical obstacles in quantum communication is the reliable transmission of quantum entanglement over long distances. Entanglement is fundamental to building large-scale quantum networks, yet photons traveling through optical fibers experience gradual loss, severely limiting the range over which entanglement can be directly maintained.

Figure 1. Quantum Internet Milestone: 100 km of Secure Communication.

This limitation has also constrained quantum key distribution, which is central to secure quantum communication. Although device-independent QKD guarantees security even when the hardware cannot be fully trusted, earlier experiments were confined to distances of just a few hundred meters. Figure 1 shows Quantum Internet Milestone: 100 km of Secure Communication.

To overcome this challenge, researchers designed a quantum repeater system capable of generating entanglement between memory units at two distant nodes. By connecting these nodes through entanglement swapping, they were able to extend entanglement across significantly longer distances.

A Breakthrough in Quantum Repeater Technology

This achievement marked the first time that long-lasting quantum entanglement suitable for scalable quantum repeater systems was successfully demonstrated. By preserving entanglement far longer than the time needed to connect individual network segments, the breakthrough opens the door to practical long-distance quantum communication.

Building on this progress, the research team extended device-independent quantum key distribution beyond 100 km for the first time. This milestone represents a major step toward scalable quantum repeaters, achieved through the simultaneous realization of high-fidelity, long-distance atom–atom entanglement.

Jiawei Pan, a leading member of the research team, an academician of the Chinese Academy of Sciences, and Executive Vice President of the University of Science and Technology of China, emphasized the significance of quantum repeaters, describing them as the “building blocks” for connecting universal quantum computers within the next 10 to 15 years.

Source: SciTECHDaily

Cite this article:

Priyadharshini S (2026), Quantum Internet Advances with 100 km Secure Communication Breakthrough, AnaTechMaz, pp.441