Quantum experiments at space scale. Credit: NSSC
China has launched the world's first quantum communication satellite - Quantum Experiments at Space Scale (QUESS) on 17th August 2016. It is designed to establish ‘hack-proof’ quantum communications by transmitting uncrackable keys from space to the ground, and provide insights into the strangest phenomenon in quantum physics - quantum entanglement - according to news agency Xinhua. Quantum communication boasts ultra-high security because a quantum photon can neither be separated nor duplicated. It is hence impossible to wiretap, intercept or crack the information transmitted through it.
In addition to quantum communications, there are quantum computers that have also drawn attention from scientists and governments worldwide. They harness the weird properties of the minute particles, which can communicate instantaneously across vast reaches of space, and exist in numerous locations and states simultaneously a phenomenon known as “superposition.” [The noted interpretation of this is the thought experiment of Schrodinger's cat - a scenario that presents a cat which may be simultaneously both alive and dead - see my earlier blog: http://www.solarancestor.com/weekly-bulletin/the-physics-behind-schrodingers-cat-paradox ] A number of different hardware technology platforms have been proposed for quantum computers, including “superconducting,” “ion trap” and Marjorana Fermion,” but using photons as the building blocks of new processors is the leading contender. All these systems have complications, and although photons have the additional challenge of moving around at the speed of light, this will help in connecting distant computers.
Chinese scientists say that a quantum computer will take just 0.01 second to deal with a problem that costs Tianhe-2, one of the most powerful supercomputers in the world, 100 years to solve. They will be able to crack all existing information encryption systems, creating an enormous security headache one day. Therefore, quantum communications, such as the QUESS satellite, will be needed to act like a "shield," protecting information from the "spear" of quantum computers, offering the new generation of cryptography that can be neither wiretapped nor decoded.
With the help of the new satellite, scientists will be able to test quantum key distribution between the satellite and ground stations, and conduct secure quantum communications between Beijing and Xinjiang's Urumqi. In its two-year mission, QUESS, is expected to beam entangled photons to two earth stations, 1 200 km apart, in a move to test quantum entanglement over a greater distance, as well as test quantum teleportation between a ground station in Ali, Tibet, and itself.
After it enters a sun-synchronous orbit at an altitude of 500 km, the 600 kg satellite will circle our planet once every ninety minutes. The satellite is nicknamed "Micius," after a fifth century B.C. Chinese philosopher and scientist who has been credited as the first one in human history to conduct optical experiments, according to the Chinese Academy of Sciences (CAS). [Source: Xinhua]