QESS What? China’s Advancement in Quantum Communications

Ms. Prarthana Basu, Research Assistant, Institute of Chinese Studies

Next month, that is, August 2018 marks the completion of China’s 600kg ‘Micius’ satellite into the low earth orbit. ‘Micius’, the quantum satellite nicknamed after a famous fifth century BC Chinese philosopher and scientist (墨子 Mozi in Chinese), is a remarkable feat in space deployment achieved by China in the field of quantum communications. The prospects of quantum communications are immense and can be applied to both civilian domains like e-commerce and military aspects by providing a hundred per cent secure link for the transfer of confidential data.

Notably, it is the world’s first “hackproof” satellite and its deployment has opened up an entire new arena in outer space technologies, giving China quite a leeway, ahead of major space powers such as US and Russia. China has further plans to develop technologies that provide for impenetrable communication links, which is why they intend to conduct more tests related to quantum communications. Quantum communication links are clearly an upgrade of the existent communication links where communication works on the principle of quantum key distribution in which cryptographic keys are transmitted in the form of light pulses. The transmission of data remains intact due to a phenomenon known as quantum entanglement where the particles mimic the same quantum state, irrespective of the spatial difference between them. A slight manipulation or disturbance (in the form of a hacking attempt or eavesdropping) would disrupt the quantum state resulting in the loss of the data link.

A landmark quantum encrypted video-conference, which lasted for about 75 minutes, was held in September last year between China and Austria, covering a distance of roughly 1200 kilometres. Anton Zeilinger, a pioneer in the field of quantum communications has termed the video-conference as ‘very important and impressive’. European researcher Ronald Henson from the Technical University of Delft, Netherlands has also applauded China’s successes and commented that ‘This is the first demonstration of intercontinental quantum key distribution of any kind, and it will stand as a milestone towards future quantum networks’. This indeed has been proven to be an important milestone for China as a country and its scientific community who have been working on it, including various other projects, in order to be at par with other global powers such as the US and Europe. For Pan Jianwei, the lead scientist of QESS said, ‘The satellite marks a transition in China’s role from a follower in classic information technology (IT) development to one of the leaders guiding future IT achievements’.

Quantum Experiment at Space Scale (QESS) is an international research project, which China has been working on, since 2011. The White Paper released by China titled ‘China’s Space Activities’ in 2016 discusses China’s breakthrough in Space Science and highlights ‘quantum experiments in space’ as one of the major thrust areas. It also mentions about ‘quantum communications and computing’ under the science and technology programme that were to be carried out as a part the programme for Sci-Tech Innovation 2030. The Sci-Tech Innovation 2030 is an integral part of the science and technology programme and has been one of the major areas of focus for China as it continues its aspirations to become a space faring nation; this has also been repeatedly emphasized by China’s President Xi Jinping. QESS largely works under the ambit of Quantum Physics and aims to test the principles of quantum entanglement and quantum key distribution. Albert Einstein, one of the prominent scientists who produced works on quantum physics quoted the quantum entanglement phenomenon as a “spooky action at a distance”. However unwelcome in the earlier part of the 20th century, the idea has now gained currency in the 21st century in the experiments conducted by countries such as China and Austria.

There were certain scientific objectives enumerated by the National Space Science Centre of the Chinese Academy of Sciences (CAS) guiding the QESS plan: implementation of long-distance quantum communication network to provide transmission of data in a secure manner, based on the application of quantum cryptography, which has established a high-speed quantum key distribution between the satellite and the ground stations. The second objective that has been enumerated is to test quantum entanglement distribution and quantum teleportation on space scale. It is too soon to comment on the full proven successes of the QESS as it is still in its engineering qualification model phase.

In order to further advance the development in quantum experiments, Antonia Zeilinger emphasized the importance of constructing more ground stations in Europe and also creating a ground network of optic fibres (something which China is already progressing in). Xinhua commented that the country hopes to ‘achieve Asia-Europe intercontinental quantum key distribution in 2020 and build a global communication network in 2030’. Reportedly, China intends to create more quantum satellites in order to facilitate long distance quantum communications with a larger area coverage. Tests are also scheduled to take place between China and Canary Islands (West Coast of Africa), thereby expanding the area coverage over half of Asia and some parts of the African continent. China has also established a 2000 km long quantum fibre link connecting Beijing to Shanghai in the month of September 2017. Sources suggest that the successful tests on quantum communications would provide a secure communication backbone network, which would aid in the creation of strategic spaces in Beijing-Tianjin-Heibei and the Yangtze River economic zone. According to the National Interest, China’s scientists have plans to conduct a follow-up experiment with a quantum satellite placed at a higher orbit (probably GEO) within the next five years, which would provide larger geographical coverage. The future plans also include upgradation of the Chang’e Programme (China’s Moon Programme) by sending a quantum satellite to one of the gravitationally stable points between the Earth-Moon system, which would provide more scope to research on the structure and gravity of the spacetime.


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