September 30, 2024 -- Researchers from Saarland University (UdS) have achieved an important breakthrough in Quantum Communication by demonstrating Quantum Entanglement and Teleportation over a 14 km long fiber link, the “Saarbrücken Quantum Communication Fiber Testbed”.

The physicists, led by the professors Dr. Jürgen Eschner and Dr. Christoph Becher, used photon pairs in which the states of two light particles are entangled, i.e. their states are random but always correlated. One of the entangled photons is transmitted via the optical fiber to the University of Applied Sciences (htw), while the other interacts with a single atom in the UdS lab. This interaction enables the state of the atom to be teleported to the photon at the htw – a remarkable step for future quantum communication networks. The results of the experiment have now been published in a paper.

A special challenge was that the fiber link runs partly above ground and is therefore exposed to external influences such as wind and weather, which makes it difficult to transmit information on the sensitive light particles. To overcome this, the scientists continuously measured and compensated for potential interference. This makes the results of the experiment particularly valuable, as they show that Quantum Communication is possible even under difficult conditions.

The researchers are now planning to use Quantum Entanglement to create Quantum Keys for secure information transmission. In addition, the Saarbrücken testbed is to become part of a Germany-wide Quantum Network that will be used for secure communication and data exchange between Quantum Computers.