The field of quantum communications and technologies that use quantum particles as carriers of information is currently undergoing rather rapid development. This type of communication is considered to be more secure than any other type, and in the distant future quantum communication will become the main and only type, on the basis of which a quantum version of the modern Internet will function.
Considering all said above, it is possible to suppose that some technically advanced extraterrestrial civilization also went in this direction and achieved certain success. Moreover, it is high time for scientists engaged in search of signals of extraterrestrial origin to pay attention to possibility of reception of quantum messages, thanks to technology we have now.
Let us remind our readers that the main problem of quantum communication in open space is decoherence. This phenomenon occurs when quantum particle, carrying information in form of its quantum state, is influenced by some unfavorable environmental factor. Under the influence of decoherence, the quantum state of the particle is destroyed and it, the particle, becomes useless.
A team of scientists from the University of Edinburgh has carried out a number of calculations and simulations to find out at what distances in space quantum entanglement can operate. It turns out that given the low density of matter in outer space, photons can travel distances of hundreds of thousands of light years or more while remaining unharmed. Here it should be noted that we are now talking about X-ray photons, photons visible range does not have the same potential and can not freely cross the entire Milky Way.
The results obtained by scientists have already enabled them to develop strategies to search for quantum messages from extraterrestrials. One of the most promising avenues is the use of quantum entanglement, which involves the instantaneous teleportation of quantum information from one particle to another. Since this technology requires the use of both quantum and ordinary optical components, it will facilitate the search process and enable unambiguous identification of any quantum messages in signals of extraterrestrial origin.