Chinese scientists have realized the world's longest quantum secure direct communication (QSDC) of 100 kilometers, according to a recent study.

The study, jointly conducted by a team of scientists from Tsinghua University and the Beijing Academy of Quantum Information Sciences, was published in early April in the journal Light: Science & Applications.

"QSDC securely and reliably transmits information through a quantum channel with both noise and eavesdropping. Compared to classical communication where reliable transmission of information over a noisy channel is concerned, QSDC has the additional capability to ensure its security using the properties of quantum information carriers," the authors wrote. 

Rapid progress has been made in QSDC in recent years. For practical application, it is important to improve performance, such as the communication distance and the secure information rate, according to the study.

Before this breakthrough, the longest QSDC distance published was 18 km.

"QSDC has attracted much attention, and has become one of the strongest candidates for secure communication in the future," they wrote, adding "it has great potential for 6G wireless communication."

China has been advancing the industrial application of quantum technology. It has achieved a series of breakthroughs in quantum technology in recent years, including the world's first quantum satellite, a 2,000-km quantum communication line between Beijing and Shanghai, and the world's first optical quantum computing machine prototype.

(With input from Xinhua)