China Smashes Quantum Transmission Record With 2.38 kbps Speed Over 65 Miles

Chinese scientists established a new world standard in quantum communication through their achievement of transmitting 2.38 kilobits per second (kbps) data over 65 miles (104.8 km) through Quantum Secure Direct Communication (QSDC). The publication in Science Advances on February 21 introduced a crucial advancement which will help establish practical quantum-secure communication networks.

QSDC represents a groundbreaking data transmission method which employs quantum states of photons to deliver information directly through a system that does not need encryption keys like conventional QKD. QSDC provides built-in security because any unauthorized interception modifies quantum states which enables detection of such attempts. The new technology enables the development of a secure quantum internet that will use qubits instead of classical bits to achieve ultra-secure communication.

The research team composed of Long Guilu from Tsinghua University and the Beijing Academy of Quantum Information Sciences established a quasi-QSDC protocol through single-photon transmission in one direction. The technique maintains signal integrity while boosting the reliability of long-distance transmissions. The recent QSDC record surpassed previous 2022 results by achieving 0.54 bits per second transmission across 62 miles (100 km) distance.

During one week of testing the researchers achieved dial-up internet speed equivalents of 4.08 kbps through their experiments at 31.3-mile (50.3-km) distances. The researchers predict they will achieve transmission speeds that are two to three times faster than present rates and push the distance further than 93 miles (150 km).

The technological breakthrough presents critical security and financial protection and military communication challenges for the nation. Research teams predict the development of a protected worldwide network which will unite space-based systems with those of air, sea and ground networks to create a functional quantum communication system.