Chinese scientists make major breakthrough in scalable quantum networks

(ECNS) - Chinese scientists have made significant progress toward building long-distance quantum communication networks, developing scalable quantum repeater modules and setting a new benchmark in quantum-secure communication, the University of Science and Technology of China said Thursday.

The findings were published this week in studies by a research team led by physicist Pan Jianwei.

One study, published Tuesday in Nature, demonstrated for the first time a scalable basic module for quantum repeaters - a key technology designed to overcome signal loss in optical fibers, which has long limited the range of quantum networks.

The second study, published Friday in Science, showed that the team successfully extended device-independent quantum key distribution, considered the highest level of secure quantum communication, to distances exceeding 100 kilometers of fiber-optic cable.

The researchers said they also achieved long-lived quantum entanglement, lasting longer than the time required to establish it - a major technical hurdle in quantum repeater development.

The results mark a shift for fiber-based quantum networks from theoretical concepts toward practical implementation.

Quantum information science ultimately seeks to build efficient and secure quantum networks, which depend on the ability to distribute quantum entanglement deterministically over long distances.

In practice, however, signal loss in conventional optical fibers remains the main obstacle to scaling such networks, sharply weakening quantum signals over extended transmission ranges.

(By Zhang Jiahao)