New Paper on Quantum Teleportation published:
In recent years, Quantum Networks have increasingly gained importance in research. They could not only enhance the security of critical infrastructures but also enable new applications – from the secure networking of Quantum Computers to a future Quantum Internet. This requires the reliable and high-frequency generation of flying qubits as well as the teleportation of their states over long distances. Large-scale Quantum Networks need the capability to transmit Quantum Information between nodes that are far apart.
For this task, photons are currently considered the most promising candidates: they are compatible with existing communication infrastructure, robust against decoherence, and possess easily manipulable degrees of freedom. In particular, the polarization degree of freedom has proven optimal for the distribution of Quantum States and Quantum Correlations over long distances due to its flexibility and low susceptibility to noise. However, the global distribution of photons is inevitably affected by noise and losses along the transmission path, highlighting the need for Quantum Relays and Quantum Repeaters. These can compensate for losses by transmitting Quantum Information.
Despite significant advances in the performance of deterministic photon sources, it remains a challenge to use different Quantum Emitters to realize a functioning Quantum Relay between widely separated participants. An international research team – including scientists from the QR.N consortium at the Paderborn, Garching, Würzburg, and Karlsruhe sites – has now taken an important step in this direction. In a new paper, they show how this challenge can be overcome by using dissimilar Quantum Dots.
In the experiment, the researchers prepared two dissimilar semiconductor Quantum Dots so that they were suitable for the teleportation of polarization qubits. Their electronic and optical properties were specifically tuned using light–matter interaction, multi-axial strain, and magnetic fields. The demonstration was carried out in a hybrid Quantum Network using near-infrared photons: part of the connection was via optical fiber, and another part via a 270-meter free-space optical link on the campus of Sapienza University in Rome. The teleportation protocol relied on GPS-based synchronization, ultrafast single-photon detectors, and active stabilization systems to compensate for atmospheric turbulence. The resulting teleportation fidelity reached up to 82 ± 1 %, exceeding the classical limit by more than ten standard deviations – a clear demonstration of successful teleportation across a hybrid Quantum Network under real-world conditions. Click here for more information.
Source reference: https://www.nature.com/articles/s41467-025–65911‑9