The use of photons and quantum physics in the communications domain has seen traces of activity in the recent past. In August, last year, we had the world's first prototype of a working quantum radar. It used a pair of low-energy entangled photons as a means of gauging information about the surroundings.
Now, China has developed the world's first mobile quantum satellite station. The mobile, portable satellite station leverages the intrinsic properties of photons for establishing a secure channel for transmitting and receiving quantum communications. And the station has been successfully connected to Mozi, which was the world's first quantum communications satellite developed back in 2016.
Subsequently, the team of researchers led by Ji-Gang Ren at the University of Science and Technology of China in Hefei used the portable station to perform quantum key distribution. In quantum key distribution, photons are exchanged as 'keys' to encrypt or decrypt information. For demonstrative purposes, the team relayed a quantum key between the mobile satellite station in Jinan and a fixed station in Shanghai through Mozi.
While the portable quantum satellite station transmits data at a rate of between 4,000 and 10,000 bits per second, compared to a rate of about 40,000 bits per second for larger stations, impressively, the entire station setup weighs around 80 kg (176 lbs).
According to Ren, the project was backed by firms and organizations including the Industrial and Commercial Bank of China, who wanted a setup that did not require expansive, purpose-built infrastructure for the procedure. "We want more and more users to use quantum keys to protect their important information," Ren added and announced that the team plans on launching a quantum nanosatellite in the next couple of years.