Interestingly, not only did scientists successfully transmit single-photon qubits over hundreds of miles for the first time ever, but they managed to do it for six input states, and ‘demonstrate that the quantum teleportation is universal.’
Physicists from China and Austria have conducted the first intercontinental teleportation of particles through the Mozi quantum communications satellite and made a conference call impossible to hack, the Chinese Academy of Sciences press service reported.
“One year after the launch of Mozi, we have succeeded in taking three main steps towards the ‘quantum Internet,'” Chinese scientists said.
Physicists claimed to have transferred quantum keys from the satellite to Earth at a distance of 1,200 kilometers, connecting two different points on the surface of the planet at a similar distance, as well as carrying out the first orbital quantum teleportation experiments.
“Thanks to this we have improved the quality of communication 20 times compared to fiber optic systems,” added the scientists.
Modern quantum technologies are based on the phenomenon of quantum entanglement. This phenomenon, in particular, plays an important role in protected quantum communication systems, which completely exclude the possibility of espionage due to the fact that the laws of quantum mechanics prohibit the ‘cloning’ of the state of light particles.
Quantum entanglement is a property predicted in 1935 by Einstein, Podolsky, and Rosen in their formulation of the so-called EPR paradox.
Entanglement is a quantum phenomenon, with no classical equivalent, in which the quantum states of two or more objects must be described by a unique state involving all the objects of the system, even when the objects are spatially separated. This leads to correlations between observable physical properties.
The entanglement is the basis of technologies in a development phase, such as quantum computing, or quantum cryptography, and has been used in quantum teleportation experiments.
According to the press service of the Chinese Academy of Sciences, the Mozi was first used for practical purposes.
Chunli Bai, president of the Chinese Academy, and Anton Zeilinger, director of the Austrian Academy of Sciences, held the first session of an intercontinental quantum video conference, protected from ‘hacking’ by means of keys transmitted by satellite.
In order to carry out this experiment, Chinese scientists combined the satellite channels of quantum communication with the existing terrestrial quantum network that connects Beijing, Shanghai and several other Chinese cities.
A similar network was built between Vienna and the city of Graz, where there are quantum cosmic communication stations.
“Private and secure communications are fundamental human needs,” the statement read.
“In particular, with the exponential growth of Internet use and e-commerce, it is of paramount importance to establish a secure network with global protection of data.”
“Traditional public key cryptography usual relies on the perceived computational intractability of certain mathematical functions.”
“In contrast, quantum key distribution (QKD) uses individual light quanta (single photon) in quantum superposition states to guarantee unconditional security between distant parties.”
These networks and the Mozi helped to establish a connection between Beijing and Vienna, where the heads of the Academies work.
The Chinese press service added that Chinese scientists are planning to conduct similar experiments with the participation of colleagues from Russia, Singapore, Italy, and Germany.
Reference Phys.org