China’s Micius satellite has become the first in the world to have successfully sent an “unbreakable” Quantum Code to the Earth. According to state media Xinhua, this quantum teleportation experiment involved beaming up the quantum states of photons from a ground station to the satellite and then sending the keys back from the satellite to ground stations.

Micius was launched to demonstrate hack proof communication technology

Micius satellite was launched in August 2016 with an aim to demonstrate hack proof Communication Technology. This satellite, weighing more than 600 kg, is currently orbiting the Earth at an altitude of 500 kilometers.

Micius derives its name from a Chinese scientist, who was born in 5th century B.C. and is believed to be the first person ever to have carried out several optical experiments.

Pan Jianwei, an academician at state-run Chinese Academy of Sciences and the lead scientist of Quantum Experiments at Space Scale (QUESS) Experiment says quantum teleportation technology allows transfer of unknown quantum states from one object to another over a long distance. The main feature of such a communication is that an object doesn’t need to physically travel from one place to another.

Quantum teleportation technique

Long-distance teleportation is considered a fundamental element in protocols involving distributed quantum computation and large-scale quantum networks.

However, such experiments, so far, have been carried out over a distance of not more than 100 kilometers because of the loss of photon in terrestrial free-space channels or optical fibers.

The first experimental verification of quantum teleportation was carried out in 1997 by Austrian quantum physicist Anton Zeilinger. In the past 20 years, scientists have got success in demonstrating quantum teleportation using different physical systems, such as ions, electrons, atoms, etc.

Scientists are also aware of the fact that to create a global-scale quantum internet, they need to extend the range of teleportation to thousands of miles—a big challenge achieve. A solution, however, lies in exploiting space-based links that could greatly reduce channel loss while establishing a communication between two remote places on Earth.

In the latest experiment by Chinese scientists, quantum states of photons were transmitted from a ground station (located in Ali Prefecture in Tibet) to Micius satellite. The satellite then sent quantum keys back to two different ground stations—located in Nanshan (near Urumqi) and in Xinglong (Hebei Province). The communication distance between the two ground stations and the satellite varied from 645 km to 1,200 km. The transmission rate of the communication was found to be more efficient (up to 20 orders of magnitude) than an optical fiber.

According to Jianwei, this technology would enable safe transmission of a large amount of bank data over long distance. Any attempt to snoop the quantum channel will automatically introduce a detectable disturbance in the system. And if a hacker succeeds in intercepting the code/information, the information will instantly destruct itself.

Details results of this experiment have been published in the journal Nature.