At Paderborn University, Klaus Jöns and his collaborators have reported a milestone result in optical quantum communication: the successful teleportation of a single photon’s polarization state between two physically separate quantum dots. The work is part of a long-running European effort to develop quantum-network components based on semiconductor devices. Although quantum teleportation has been demonstrated before, previous experiments relied on photons produced by the same emitter. The ability to teleport a quantum state between independent solid-state sources is a step toward scalable quantum communication systems.
Laneve, A., Ronco, G., Beccaceci, M., Barigelli, P., Salusti, F., Claro-Rodriguez, N., de Pascalis, G., Suprano, A., Chiaudano, L., Schöll, E., Hanschke, L., Krieger, T. M., Buchinger, Q., Covre da Silva, S. F., Neuwirth, J., Stroj, S., Höfling, S., Huber-Loyola, T., Usuga Castaneda, M. A., … Trotta, R. (2025). Quantum teleportation with dissimilar quantum dots over a hybrid quantum network. Nature Communications, 16(1), 10028. https://doi.org/10.1038/s41467-025-65911-9
Quantum dots, which behave like artificial atoms embedded in semiconductor structures, can emit single photons with well-defined quantum states. Telecom groups, quantum optics labs and photonic-chip researchers have been exploring them as potential building blocks for a future quantum internet. One of the challenges has been ensuring that two separate quantum dots can generate photons of sufficiently similar quality for entanglement and teleportation protocols. Even small differences in emission frequency or line shape can disrupt the interference required for these processes to succeed.
Klaus Jöns from Paderborn University stated,
“Previously, these photons came from one and the same source, i.e., the same emitter. Although there has been significant progress made in recent years, using distinct quantum emitters to implement a quantum relay between independent parties had previously remained out of reach”.
The teams involved in this project addressed that difficulty by combining careful nanofabrication with active stabilization of the optical link. The quantum dots used for the experiment were grown at Johannes Kepler University Linz, and the micro-resonators that enhance their emission were fabricated at the University of Würzburg. The teleportation experiments took place at Sapienza University of Rome, where the researchers constructed a 270-meter free-space optical link between two buildings. This arrangement allowed them to simulate conditions relevant to practical urban-scale deployments.
To synchronize the operations at both ends of the link, the team used GPS timing signals along with fast single-photon detectors and optical stabilization systems that counteracted atmospheric turbulence. Systems of this type are increasingly common in free-space quantum key distribution trials, and their integration here demonstrates how similar technologies may support more complex quantum protocols. The reported teleportation fidelity, about 82 percent, exceeded the classical limit by a wide margin, indicating that the state transfer preserved the essential quantum characteristics of the photon.
Researchers across Europe have been working toward this goal for more than a decade. Jöns and Rinaldo Trotta of Sapienza University developed an early roadmap for using quantum dots to generate entangled photons and implement teleportation schemes. As the field has advanced, techniques for tuning quantum dots—either by strain, electric fields, or temperature—have improved, making it more feasible to align two dissimilar emitters. The present experiment demonstrates that such tuning, paired with optimized fabrication and optical engineering, can yield quantum sources suitable for long-distance protocols.
The work also aligns with broader progress in solid-state quantum networking. Around the same time, a research team in Stuttgart and Saarbrücken reported a similar achievement using frequency conversion to match photons from distinct emitters. Techniques like these may eventually allow heterogeneous quantum hardware to interoperate, helping form the basis for a distributed network in which different types of quantum nodes contribute specific strengths.
With the success of single-photon teleportation between independent quantum dots, the next steps include demonstrating entanglement swapping between two deterministic photon sources. That process would allow the creation of entanglement between nodes that have never interacted directly, enabling true quantum relays. Such relays could extend the distance over which quantum information can be transmitted without loss, a prerequisite for a functional quantum internet.
The present findings illustrate how sustained collaboration across materials science, nanofabrication and optical engineering can gradually turn theoretical quantum-network concepts into experimental demonstrations. As techniques continue to improve, semiconductor-based photon sources may become foundational components of secure communication systems and distributed quantum-computing architectures.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
