Germany Launches Its First Quantum Internet Node

The Fraunhofer Institute for Laser Technology (Fraunhofer ILT), which co-developed the system with the Netherlands Organization for Applied Scientific Research (TNO), is delivering what is being dubbed “the first node for the quantum internet of the future” to the German state of North Rhine-Westphalia on January 28, 2024. The system will undergo testing and development, with the first regional connections anticipated to be established between Jülich and Bonn and Aachen, where it now resides. 

Under the direction of QuTech in Delft, the Netherlands, the multinational team is creating metropolitan-scale quantum networks to connect quantum computer platforms, give users from industry and research access to quantum computers, and enable the use of entangled qubits for the safe encryption of private information. 

Up until now, these networks have only been able to be put into place locally or regionally. Because there are no repeaters to enhance messages sent by individual photons without breaking quantum entanglement, long-distance links have proven difficult to establish. 

With support from TNO and the Technical University of Delft (TU Delft), the research team led by QuTech was able to connect two quantum computers in Delft and The Hague over 25 km of subterranean optical fiber. They were also able to replicate the creation of quantum entanglement along the fiber. 

TNO and Fraunhofer ILT collaborated to update the design, making it simpler to swap out individual parts while testing. The institute in Aachen also provided a number of optical assemblies. The new node was delivered to Aachen in mid-January following assembly and a test operating phase that included its characterization at TNO in Delft. 

Bernd Jungbluth, leader of Fraunhofer ILT's Quantum Technologies strategic initiative, stated, "We envision that metropolitan scale quantum networks will enable very powerful, secure connections between quantum computers and between quantum sensors." 

According to the scientists, the breakthrough will enable applications such as distributed quantum computing, which connects multiple computers to create a quantum system, to rapidly grow their performance and capacity. Moreover, secure remote access to quantum computers—which are now only partially accessible—requires quantum networks. The researchers think that a link between the Aachen node and the Helmholtz Quantum Center on the Jülich quantum campus might make these a reality. Jungbluth said there are also plans to connect to the backbone of a central German test network in Bonn. 

Along with QuTech and Fraunhofer ILT, the project also featured a number of other businesses, including TOPTICA Photonics AG, a specialist in highly stable lasers; Element6, a provider of synthetic diamonds and qubit chip substrates; and OPNT B.V., a Dutch timing hardware specialist.