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Satellite-based entanglement distribution over 1200 kilometers
Juan Yin1,2, Yuan Cao1,2, Yu-Huai Li1,2
1Department of Modern Physics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.
Science (New York, N.Y.)
|June 17, 2017
Summary
Satellite-based quantum networks achieved long-distance entanglement distribution over 1203 km, overcoming previous distance limitations. This breakthrough enables foundational quantum physics tests and scalable quantum networks.
Area of Science:
- Quantum physics
- Quantum communication networks
Background:
- Long-distance entanglement distribution is crucial for quantum physics tests and quantum networks.
- Previous distance limitations (~100 km) were primarily due to channel loss.
Purpose of the Study:
- To demonstrate satellite-based distribution of entangled photon pairs over unprecedented distances.
- To overcome the limitations of terrestrial fiber-based entanglement distribution.
Main Methods:
- Utilized a satellite platform for distributing entangled photon pairs.
- Employed two satellite-to-ground downlinks with varying lengths (1600-2400 km).
- Ensured strict Einstein locality conditions for measurements.
Main Results:
- Successfully distributed entangled photon pairs over 1203 km between two ground locations.
- Confirmed the survival of two-photon entanglement.
- Observed a violation of Bell inequality (2.37 ± 0.09), confirming quantum correlations.
- Achieved significantly higher effective link efficiency compared to direct fiber transmission.
Conclusions:
- Satellite-based distribution is a viable method for long-distance quantum entanglement.
- This technology overcomes previous distance limitations, paving the way for global quantum networks.
- The results support foundational tests of quantum mechanics over large distances.
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