New world record!

On May 6, the reporter learned from the University of Science and Technology of China that the school's academician Pan Jianwei and his colleagues Peng Chengzhi, Chen Yuao, Yin Juan, etc., using the "Micius" quantum science experimental satellite, recently realized for the first time the remote transmission of quantum states between two ground stations 1,200 kilometers apart on the earth, taking an important step towards building a global quantum information processing and quantum communication network.

Using 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. How to break through the transmission distance limitation has always been one of the core issues in international quantum communication research.

The world's first quantum science experimental satellite "Micius" launched by China provides a new platform for human exploration of long-distance quantum communication. However, due to the influence of atmospheric turbulence, it is very difficult to achieve quantum state measurement based on quantum interference after photons propagate in the atmospheric channel.

At the Ali Observatory in Tibet, the "Mozi" quantum science experimental satellite passed by, and researchers were conducting experiments (photographed on December 10, 2016, composite photo). Photo by Xinhua News Agency reporter Jin Liwang

Recently, Pan Jianwei's team innovatively applied optical integrated bonding technology to the field of space quantum communication, realizing an optical interferometer with ultra-high stability, which can be long-term stable without active closed loop, overcoming the problem of quantum light interference after long-distance turbulent atmospheric transmission. They combined the quantum teleportation scheme based on the two-photon path-polarization mixed entangled state, completed the transmission verification of remote quantum states between the Lijiang Station in Yunnan, China and the Delingha Ground Station in Qinghai, and verified six typical quantum states in the experiment, and the transmission fidelity exceeded the classical limit.

In 2012, Pan Jianwei's team achieved the world's first free-space quantum teleportation over 100 kilometers. Ten years later, they successfully achieved a breakthrough and set a new world record of 1,200 kilometers of surface quantum state transmission.

Pan Jianwei, chief scientist of China's "Micius" quantum science experimental satellite, takes a photo with the "Micius" quantum satellite model in his office at the University of Science and Technology of China (photo taken on December 13, 2018). Xinhua News Agency reporter Zhang Duan

The results were recently published in Physical Review Letters, an internationally renowned academic journal. The reviewer believes that "this experiment is more challenging than previous experiments, overcame major technical challenges, and is of great significance for future quantum communication applications."

Source: Xinhua News Agency