The world’s first integrated quantum communication network was revealed by scientists in Japan. The ground segment connects Beijing and Shangai over a distance of 2,000 kilometers (1,200 miles) and is composed of 700 optical fibers. The entire network has a coverage area of 4,600 kilometers when combined with China’s Quantum Satellite (2,860 miles). The network’s specifics are described in Nature.
The field of computers could undergo numerous revolutions because of quantum computing. The development of practically impenetrable communications is a really intriguing prospect. Read access to said messages will be restricted to users possessing secure quantum keys.
Using the quantum states of particles—in this case, photons—quantum keys are produced. Not even the most potent supercomputer can estimate or compute these states. The particle is either in that state or it is not. Additionally, you are unable to join in on the discussion. If you were to “eavesdrop,” you would be altering the characteristics of the particles and making it seem that the key has been altered without giving you access.
On the other hand, because these quantum keys’ qualities are easily broken, it is more difficult to transfer them. For several years, researchers have been working to enhance quantum key distribution (QKD). They created a brand-new technology for the ground-based components dubbed Twin-Field QKD, which made it possible to transmit keys four times farther than was previously possible.
With the help of the Micius satellite, tests and enhancements carried out in recent years have allowed them to achieve a QKD of 47.8 kilobits per second on the satellite-to-ground portion of the network, which is 40 times faster than their previous record. The team emphasizes that since its channel loss is similar to that of real geostationary satellites, the deployment of quantum satellites in geostationary orbit may be feasible in the future.
According to a study statement, “Our work demonstrates that quantum communication technology is sufficiently mature for large-scale practical applications.”
This achievement demonstrates that nations can create their own global quantum networks and subsequently merge them. China already has plans to engage with overseas partners in Russia, Austria, Italy, and Canada to broaden the network. A national quantum internet network is also being investigated in the United States; the Department of Energy released a roadmap for it in July of last year.
Diversifying the applications of quantum satellite technology will be one of the next steps. Small, inexpensive satellites for low-Earth orbit are to be built, along with more sophisticated systems that may be stationed in geostationary orbit.
