Latest news with #BeijingAcademyofQuantumInformationSciences
South China Morning Post
6 days ago
- Science
- South China Morning Post
God's play? Chinese scientists catch cosmic rays meddling in quantum computer operation
Researchers in China said they have found the first evidence that subatomic particles from cosmic rays may be affecting the efficiency of widely used error correction techniques that are an essential element of fault-tolerant quantum computing. The scientists monitored superconducting quantum chips alongside fundamental subatomic particles – called muons – produced by cosmic rays , as well as gamma ray-induced particle disturbances known as quasiparticle bursts. 'We directly observed quasiparticle bursts leading to correlated errors that are induced solely by muons and separated the contributions of muons and gamma rays,' they said in a paper published last month by the peer-reviewed journal Nature Communications. The findings could be significant for the scaling of quantum processors and the design of fault-tolerant quantum computing systems, which can function properly even if faults or errors are present, the scientists said. According to the team – from the Chinese Academy of Sciences, the Beijing Academy of Quantum Information Sciences and Nanjing Normal University – the proposed detection method could also be applied in cosmic ray and dark matter particle detection. Unlike traditional computing's unit of information that exists either as 0 or 1, its quantum counterpart relies on quantum bits or qubits that can exist in a multidimensional state, making possible more advanced and secure tasks. However, errors can occur simultaneously in multiple qubits. On a small scale, these multiqubit correlated errors can be reduced with optimised error correction methods, though the efficacy of these strategies diminishes in larger-scale computing.
Times of Oman
24-02-2025
- Science
- Times of Oman
Chinese researchers develop system for quantum direct communication
Beijing: A team of Chinese researchers proposed a theory of one-way quantum direct communication and successfully developed a practical system, advancing quantum direct communication from a concept to the stage of practical application. According to a study recently published in Science Advances, researchers from the Beijing Academy of Quantum Information Sciences, Tsinghua University, and North China University of Technology set a record in a standard optical fibre communication test with a transmission distance of 104.8 km. They achieved stable transmission at a rate of 2.38 kilobit per second for 168 consecutive hours. Quantum direct communication was previously proposed by a team led by Long Guilu from Tsinghua University, one of the corresponding authors of the study paper. It enables secure communication by utilising quantum states and features characteristics, such as eavesdropping detection and prevention, compatibility with existing networks, simplified management processes, and covert transmission. The core challenge in this field is achieving secure and reliable communication using quantum states with extremely low energy. These states are highly susceptible to interference in quantum channels characterised by high noise, high loss, and the risk of eavesdropping. Previous research used bidirectional protocols, in which both communicating parties had to transmit quantum states back and forth. This resulted in significant system loss and severely limited communication performance improvement. "In 2022, we set a world record for quantum direct communication over 100 kilometers, but the rate was only 0.5 bit per second, which allowed transmission of messages with very few characters," Long recalled. He explained that one-way transmission could halve the distance of quantum state transmission, significantly reducing loss, which is the key to improving the performance of quantum direct communication. The researchers developed high-noise and high-loss channel coding and other key technologies to propose a theoretical method for one-way quantum direct communication. They resolved the technical challenges and completed the development of the communication terminal. The new system's communication rate has increased by 4,760 times compared with the one developed in 2022, significantly enhancing the performance of quantum direct communication. According to Long, quantum direct communication systems are expected to be widely applied in fields with extremely high requirements for information security, such as government affairs and finance. There are two main types of quantum secure communication. One is quantum key distribution, which uses quantum states to generate keys while transmitting encrypted information through classical communication. Its advantage is the high transmission rate. The other is quantum direct communication, which directly transmits information using quantum states. In the event of eavesdropping, the quantum states can self-destruct to ensure information security.
