Long-Distance Entanglement Purification for Quantum Communication
Xiao‐Min Hua b, Cen-Xiao Huanga b, Yu‐Bo Shengc d e, Lan Zhouc d e, Bi‐Heng Liua b, Yu Guoa b, Chao Zhanga b, Wen-Bo Xinga b, Yun‐Feng Huanga b, Chuan‐Feng Lib c, Guang‐Can Guoa b c d
- aCAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
- bCAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, People's Republic of China
- cInstitute of Quantum Information and Technology, Nanjing University of Posts and Telecommunications, Nanjing 210003, People's Republic of China
- dKey Lab of Broadband Wireless Communication and Sensor Network Technology, Nanjing University of Posts and Telecommunications, Ministry of Education, Nanjing 210003, People's Republic of China
- eSchool of Science, Nanjing University of Posts and Telecommunications, Nanjing 210003, People's Republic of China
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Abstract
High-quality long-distance entanglement is essential for both quantum communication and scalable quantum networks. Entanglement purification is to distill high-quality entanglement from low-quality entanglement in a noisy environment and it plays a key role in quantum repeaters. The previous significant entanglement purification experiments require two pairs of low-quality entangled states and were demonstrated in tabletop. Here we propose and report a high-efficiency and long-distance entanglement purification using only one pair of hyperentangled state. We also demonstrate its practical application in entanglement-based quantum key distribution (QKD). One pair of polarization spatial-mode hyperentanglement was distributed over 11 km multicore fiber (noisy channel). After purification, the fidelity of polarization entanglement arises from 0.771 to 0.887 and the effective key rate in entanglement-based QKD increases from 0 to 0.332. The values of Clauser-Horne-Shimony-Holt inequality of polarization entanglement arises from 1.829 to 2.128. Moreover, by using one pair of hyperentanglement and deterministic controlled-NOT gates, the total purification efficiency can be estimated as 6.6×10^{3} times than the experiment using two pairs of entangled states with spontaneous parametric down-conversion sources. Our results offer the potential to be implemented as part of a full quantum repeater and large-scale quantum network.
TL;DRA high-efficiency and long-distance entanglement purification using only one pair of hyperentangled state is proposed and reported and offers the potential to be implemented as part of a full quantum repeater and large-scale quantum network. (Semantic Scholar)