Breakthrough in Quantum Teleportation Achieved by Researchers

An international research team, including scientists from Paderborn University, has made significant strides towards establishing a quantum internet by successfully achieving single-photon teleportation. For the first time, the polarization state of a single photon emitted from one quantum dot has been teleported to another quantum dot located at a distance. This breakthrough represents a crucial development for future quantum communication systems.

The team conducted their experiments using a 270-meter free-space optical link, demonstrating the potential for long-distance quantum communication. The results of this work have been published in the journal Nature Communications on December 2, 2025.

Collaboration and Years of Research Pay Off

The achievement is the culmination of nearly a decade of collaborative effort among doctoral and postdoctoral students at Paderborn University. Under the guidance of Professor Klaus Jöns, the team partnered with Professor Rinaldo Trotta and his group at Sapienza University of Rome. Professor Jöns noted, “The experiment impressively demonstrates that quantum light sources based on semiconductor quantum dots could serve as a key technology for future quantum communication networks.”

The teleportation of quantum states is vital for developing scalable quantum relays, which are essential for implementing a functional quantum internet. The research builds upon a roadmap established by Professors Jöns and Trotta about ten years ago, which outlined how quantum dots could be utilized as sources of entangled photon pairs for teleportation protocols.

Technical Achievements and Future Directions

The project’s success is attributed to excellent materials science, advanced nanofabrication techniques, and optical quantum technology. The quantum dots were meticulously developed at Johannes Kepler University Linz, while the nanofabrication of resonators was carried out by partners at the University of Würzburg. The quantum teleportation experiments were executed in Rome, with a sophisticated setup that included a GPS-assisted synchronization system, ultra-fast single-photon detectors, and stabilization systems to mitigate atmospheric turbulence.

The teleportation state fidelity achieved was an impressive 82 ± 1%, exceeding the classical limit by more than ten standard deviations. This high level of fidelity indicates the potential for reliable quantum state preservation during teleportation.

Looking ahead, the research team aims to demonstrate “entanglement swapping” between two quantum dots, which would mark the first quantum relay utilizing two deterministic sources of entangled photon pairs. Deterministic sources are capable of producing single photons with high reliability, a significant advancement in quantum technology.

In a parallel effort, researchers from Stuttgart and Saarbrücken have reported similar results through frequency conversion techniques, collectively marking a pivotal milestone for European quantum research.

As the field continues to advance, these achievements lay the groundwork for future developments in quantum communication, data security, and quantum computing.