International Expert Magazine emphasizes Significance for global Quantum Communication –
In mid-November, researchers from the QR.N consortium at the Stuttgart, Saarbrücken, and Dresden sites published a paper on an experiment that marks an important milestone in the development of semiconductor-based Quantum Light Sources. At the heart of the work is the successful teleportation of a Quantum State between two photons generated by different semiconductor Quantum-Dot Light Sources. These were not located in the same cryostat but in separate experimental setups. Although the relatively short distance of about one meter is not yet sufficient to fully demonstrate the operating principle of a Quantum Repeater, the experiment shows great potential for future extension to larger distances. It thus establishes an important prerequisite for the development of global Quantum Communication Networks.
This milestone on the path toward future Quantum Networks attracted considerable international attention. In mid-January 2026, Physics World published a report in which Tim Strobel, a doctoral researcher at the Institut für Halbleiteroptik und Funktionelle Grenzflächen (IHFG), Semiconductor Optics Group at the Universität Stuttgart and lead author of the paper, puts the results into context. Strobel emphasizes: “Our result is particularly exciting because such a quantum Internet will encompass these types of distant quantum nodes and will require quantum states that are transmitted among these different nodes. It is therefore an important step in showing that remote sources can be effectively interfaced in this way in quantum teleportation experiments.” He thus explains that the successful teleportation between spatially separated Quantum Sources represents a crucial step toward scalable Quantum Communication Systems that could, in the future, connect different locations worldwide.
In the experiment, frequency converters were used to precisely tune and spectrally match the wavelengths of the photons. This makes it possible to shift the original wavelengths of the photons emitted by the Quantum Dots (around 780 nm) to 1515 nm, a wavelength commonly used in telecommunications, without altering the Quantum State of the photons. Thanks to this conversion, the technology is compatible with the existing global fiber-optic network – another important step toward practical applications. The researchers now plan to transfer the quantum-dot-based teleportation technology from the controlled laboratory environment into the real world. That this is fundamentally feasible was already demonstrated in an earlier study, in which photon entanglement was maintained over a 36 km fiber-optic link across the city of Stuttgart. Further information on the paper can be found here, as well as in an official press release from the Universität Stuttgart.
Source references: https://physicsworld.com/a/quantum-state-teleported-between-quantum-dots-at-telecoms-wavelengths; https://www.nature.com/articles/s41467-025-65912-8
