By admin December 26, 2020
Teleportation? It only exists in Star Trek… and in the strange world of the infinitely small. An American-Canadian team has just carried out long-distance quantum teleportation. They succeeded, by means of an optical fiber, in teleporting information over a distance of 44 km.
Quantum teleportation has little to do with the “teleportation” of science fiction movies. It is not the particle itself that is teleported, but its state, thanks to the phenomenon of quantum entanglement described in 1935 by Einstein (who did not believe in it and thought he had missed something in his theory). To visualize the thing, you have to imagine two twins, one of which would instantly feel everything the other feels, even from millions of kilometers away. Two entangled particles behave in the same way: any modification of the characteristics of one immediately leads to the modification of the other, and vice versa.
Double the power for each additional qbit
This curious phenomenon has since been confirmed multiple times in the laboratory. But scaling up is another matter. This is what researchers from the University of Calgary (Canada), Harvard, the Caltech Institute, the Fermilab public laboratory and NASA have managed to achieve by teleporting qbits of photons through a network of fibers. quite ordinary optics of 44 km.
The qbit is the basic unit of storage in quantum computing. Unlike the bit that we know in traditional computing, the latter is not necessarily equal to 0 or 1. Until it is measured, it can be equal to both 0 and 1. This explains the craze around quantum computers: for each additional qbit, the power is doubled.
Obviously, we do not determine the state of a particle as we measure a common electrical voltage. The quantum universe, that of the infinitely small, is the realm of probabilities. Impossible, for example, to determine both the speed and the precise position of a particle: you have to choose. And a photon will behave differently depending on whether it is measured as if it were a particle or a wave.
The foundations of a future quantum internet
One of the obstacles faced by researchers in quantum computing is the reliability of the systems. From this point of view, the experience of the Fermilab researchers and their colleague is relatively conclusive, since they claim a reliability greater than 90%. This is a “significant step in the creation of a functional quantum internet”, note the authors of the study, published at the end of October in the journal PRX Quantum, but a little gone unnoticed.
During the summer, the US Department of Energy laid the foundations for a future quantum internet network linking several research institutes in Chicago. The advantages of a quantum internet would be numerous, both in terms of speed and security. In a quantum internet, it would thus be physically impossible to intercept information without altering it and being detected. (Click to Source)