Quantum entanglement: photon sent 30 miles away on optical fiber

An important step in the context of the possible use of quantum networks in computer science was carried out by a group of researchers according to what was published in a statement published on the website of the University of Innsbruck.

According to the release, a distance of 30 miles was covered for the first time, using fiber optic cables, as regards the transfer of quantum entanglement between matter and light. The experiment was performed by the team of the experimental physicist Ben Lanyon who has been studying the phenomena of the quantum world for years to understand any applications in real computing, particularly in computer networks.

The researchers trapped a calcium atom in an ion trap. Then, using laser beams, they excited the ion that emitted a photon in which quantum information is stored after the quantum states of the atom and the same light particle entered the entanglement state; that is, they remained “connected.”

The researchers then succeeded in sending this photon through a 50 km long fiber optic line. Following the submission, the researchers measured the state of the atom and of the light particle that arrived at its destination, certifying that they were still in the entanglement state.

The same researchers believe that it is possible, by creating two nodes that each send a photon entanglement over a distance of 50 km, to obtain a dispatch of 100 km, a distance that would allow the construction of the first true intercontinental quantum network.

“Only a handful of ion trap systems along the way would be needed to establish a quantum network between Innsbruck and Vienna,” report the scientists.