Chinese researchers have made a crucial breakthrough in quantum communication technology, boosting the future development of secure satellite-based long-distance and global quantum communication networks. The research team constructed a 15-user Quantum Secure Direct Communication (QSDC) network. The network enabled the direct transmission of confidential information among the users connected by the network for the first time.
Quantum communication is a cutting-edge information technology that promises ultra-secure transmission of data. Scientists have developed many models for such transmission, including quantum key distribution, quantum teleportation and QSDC.
Based on QKD technology, many different types of quantum communication networks have been proposed. However, such communication networks only transmit the key but do not directly transmit information.
In contrast, QSDC sends secret information directly over a secure quantum channel. Any attack of QSDC results in only a random number, and cannot obtain any useful information from it. Therefore, QSDC has simple communication steps and reduces potential security loopholes, and offers higher security guarantees.
In recent years, the experimental QSDC has been developed significantly. However, the inability to simultaneously distinguish the four sets of encoded orthogonal entangled states in entanglement-based QSDC protocols limits its practical application. Experimental demonstration of QSDC is required. To achieve wide applications of QSDC, they constructed the fully connected entanglement-based QSDC network, including five subnets, with 15 users. The result demonstrates the feasibility of a proposed QSDC network.
China included quantum technology as one of the new high techs in its 14th Five-Year Plan (2021-2025). China’s five-year plan (FYP) is one of the most important policy blueprints that set medium-term goals for the country’s economic and social development. Developing self-reliant technologies is expected to be one of the top priorities in its 14th FYP.
The President of China has stressed the importance and urgency of advancing the development of quantum science and technology. Quantum mechanics is a fundamental theory that has been used successfully in explaining microscopic phenomena in all branches of physics. Experts believe the whole world is on the brink of a quantum revolution.
China has made breakthroughs in some of the key areas, but still faces multiple challenges. He stressed the need to develop self-reliant technology in order to secure a stable supply chain. More support should be given to the industry in areas including development policy, talent recruiting, academic environment and so on.
Just as 5G promises to revolutionise digital communications and by doing so, spark the creation of breakthrough products and services such as driverless cars and telemedicine, quantum computing offers advances of a similar magnitude.
By integrating information technology with quantum mechanics, quantum computers deliver many thousands of times the computing power of conventional or classical computers. They do this by harnessing the three principles of quantum mechanics: superposition, entanglement and interference.
As reported by OpenGov Asia, China developed a miniaturised quantum satellite ground station. The ground station is light and portable and can be installed within 12 hours, allowing users in remote areas to use quantum communication conveniently. The piece of quantum key distribution equipment is about the same size as a laptop, which can greatly reduce the cost of quantum network building and maintenance.
In recent years, China has achieved a series of breakthroughs in quantum technology, 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.
A global quantum network can be realised by connecting more national quantum networks from different countries via ground connections or ground-to-satellite links. In the future, quantum communication will be applied in the fields of finance, political affairs and national defence. A whole industry chain and eventually a truly secure quantum internet will be possible.
