A global quantum internet relies on scalable networks, which require reliable quantum hardware. Quantum light sources provide deterministic, high-brightness, high-fidelity entangled photons and quantum memories with coherence times exceeding the millisecond range.
Researchers at [Institution] have successfully demonstrated telecom-wavelength quantum teleportation using frequency-converted photons from remote quantum dots. This achievement marks an important step towards the development of a global quantum internet.
The experiment used two remote GaAs quantum dots, emitting in the near-infrared, which were used as single-photon source and entangled-photon pair source. The single photon was prepared in conjugate polarization states and interfaced with the biexciton emission of the entangled pair using a polarization-selective Bell state measurement.
The frequency mismatch between the triggered sources was erased using two polarization-preserving quantum frequency converters, enabling remote two-photon interference at telecommunication wavelengths. This process converted the XX photons to a common telecommunication wavelength, allowing for long-distance teleportation experiments.
The researchers achieved an average teleportation fidelity of up to 0.721(33), significantly above the classical limit, demonstrating successful quantum teleportation between light from distinct sources. This result is expected to pave the way for future quantum communication applications and the development of a global quantum internet.
The experiment was conducted using a set of six superconducting nanowire single-photon detectors, which were installed in two distinct cryostats. The detectors were designed to operate at telecommunication wavelengths and had an efficiency of 85%. A time-tagging unit enabled simultaneous operation of the detectors.
The researchers used a theoretical model to simulate the experiment, taking into account experimental imperfections such as limited single-photon purity and non-zero FSS. The model also accounted for setup birefringence and non-perfect temporal mode overlap.
This achievement is significant because it demonstrates the maturity of quantum dot-based technology and its potential for future quantum communication applications. The researchers believe that this result will pave the way for long-distance teleportation experiments and contribute to the development of a global quantum internet.
The study was funded by the German Federal Ministry of Research, Technology, and Space (BMFTR) via Projects QR.X and QR.N, as well as the EU’s Horizon 2020 research and innovation program under Grant Agreement no. 899814 (Qurope).
Overall, this achievement marks an important step towards the development of a global quantum internet and demonstrates the potential of quantum dot-based technology for future quantum communication applications.
Source: https://www.nature.com/articles/s41467-025-65912-8