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Updated: Sep 23, 2025
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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Quantum State Transfer over 1200 km Assisted by Prior Distributed Entanglement
Bo Li1,2,3, Yuan Cao1,2,3, Yu-Huai Li1,2,3
1Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China.
Physical Review Letters
|May 16, 2022
Summary
This study demonstrates long-distance quantum state transfer (QST) over 1200 km using satellite-based entanglement. The quantum teleportation achieved fidelity exceeding classical limits, paving the way for secure quantum communication networks.
Area of Science:
- Quantum Information Science
- Quantum Communication
- Free-Space Quantum Key Distribution
Background:
- Long-distance quantum state transfer (QST) is crucial for quantum communication protocols.
- Atmospheric turbulence poses challenges for Bell-state measurements in free-space quantum teleportation.
- Previous experiments required local Bell-state measurements before entanglement distribution.
Purpose of the Study:
- To demonstrate proof-of-principle QST over 1200 km using a satellite-based entangled photon source.
- To overcome challenges of atmospheric turbulence in free-space quantum communication.
- To achieve high-fidelity quantum state transfer between distant ground stations.
Main Methods:
- Utilized a satellite-borne entangled photon source (Micius).
- Developed a highly stable interferometer for hybrid path-polarization projection.
- Performed quantum state transfer assisted by prior shared quantum entanglement between ground stations.
Main Results:
- Achieved QST over a distance exceeding 1200 km.
- Demonstrated an average fidelity of 0.82±0.01 for six distinct quantum states.
- Exceeded the classical limit of 2/3 fidelity for a single qubit copy.
Conclusions:
- Proof-of-principle for satellite-assisted long-distance QST is established.
- The developed methods overcome atmospheric turbulence challenges for quantum communication.
- High-fidelity quantum state transfer over global distances is feasible, advancing quantum networks.
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