The reporter learned from the University of Science and Technology of China on May 6 that academician Pan Jianwei and colleagues Peng Chengzhi, Chen Yuao, Yin Juan, etc. of the university used the "Mozi" quantum science experimental satellite to recently realize the remote transmission of quantum states between two ground stations 1200 kilometers apart on the earth for the first time, taking an important step towards building a global quantum information processing and quantum communication network.
The use of quantum teleportation to achieve long-distance quantum state transmission is an important way to build a quantum communication network. However, in the process of implementation, the distance and quality of quantum entanglement distribution will be affected by factors such as channel loss and decoherence, and how to break through the transmission distance limit has always been one of the core issues in international quantum communication research.
Mozi, the world's first quantum science experimental satellite launched by China, provides a new platform for human exploration of long-distance quantum communication. However, due to atmospheric turbulence, after the photons propagate in the atmospheric channel, it is very difficult to achieve quantum state measurements based on quantum interference.
At the Ali Observatory in Tibet, the Mozi quantum science experiment satellite transits, and researchers are doing experiments (taken on December 10, 2016, synthetic photo). Photo by Xinhua News Agency reporter Jin Liwang
Recently, Pan Jianwei's team has innovatively applied optical integration bonding technology to the field of space quantum communication, realizing an ultra-high stability optical interferometer that can be stable for a long time without active closed loop, overcoming the problem of quantum light interference after long-distance turbulent atmospheric transmission. Combining the quantum teleportation scheme based on the two-photon path-polarization hybrid entangled state, they completed the transmission verification of remote quantum states between Lijiang Station in Yunnan And Delingha Ground Station in Qinghai, China, and verified six typical quantum states in the experiment, and the transmission fidelity exceeded the classical limit.
In 2012, Pan Jianwei's team realized more than 100 kilometers of free space quantum teleportation for the first time in the world. 10 years later, they successfully achieved a breakthrough, setting a new world record for quantum state transmission at 1200 kilometers of surface.
Pan Jianwei, chief scientist of China's Mozi quantum science experimental satellite, poses with the Mozi quantum satellite model in the office of the University of Science and Technology of China (taken on December 13, 2018). Photo by Xinhua News Agency reporter Zhang Duan
A few days ago, the international authoritative academic journal "Physical Review Letters" published the results. The reviewers believe that "this experiment is more challenging than previous experiments, overcomes major technical challenges, and has important implications for future quantum communication applications." ”
Source: Central Committee of the Communist Youth League