At the LMU in Munich, scientists have for the first time succeeded in transmitting data through an entangled atom. The so-called quantum internet is thus moving a little closer.
In what direction are computers developing? Countless researchers are looking into this question. Since the invention of the modern computer, the actual concept has hardly changed. Depending on the presence of voltage, the command is interpreted as 0 (off) or 1 (on). All arithmetic operations are then based on this.
But how can this concept be developed further? The solution lies in quantum computers. A full explanation of how this works would go beyond this article. But importantly, in the future, quantum computers will communicate through tiny particles like atoms. When two particles form a bond, it is called entangled.
In Munich, the quantum internet is becoming a reality
At Ludwigs Maximilian University in cooperation with Saarland University, there is now such an entanglement for the first time made it through several kilometers. Two optically trapped rubidium atoms were used for this purpose. Two labs on campus each contained one of these atoms.
The data was then transmitted via a fiber optic cable under Geschwister-Scholl Platz. A quantum network consists of many individual nodes, quantum memories. This is done by ions, crystal lattices or the atoms used here.
Nodes can receive, store and send information through light particles. This is usually done using infrared waves, which are quickly lost in the fiber optic cable. By increasing the wavelength, the researchers solved this problem, meaning that information could flow through the fiber optic cable.
Quantum recording: communication through optical fibers
During the transmission, communication similar to that in telecommunication networks was achieved. Although the efficiency still needs to improve, it has already reached record values of around 57 percent. And the transfer happens like this: The laser beam excites the atoms so that they spontaneously fall into their ground state and each emits a photon (pulse of light).
This passes through the fiber optic cable and is received and interpreted by the atom on the other side. The result is a form of communication that is currently secured against external attacks and offers a secure communication medium.
It should be clear that there are many advantages and disadvantages to this. However, this approach shows impressively how complex the matter is. The information has so far covered a distance of 33 kilometers. It will probably be a while before we get to international broadcasts.