Performance optimization for quantum key distribution in lossy channel using entangled photons

• 来源期刊: 中国物理B（英文版）
• 关键词: quantum key distribution time of arrival quantum bit error rate key rate
• 年，卷（期）: 2017,（11）
• 页码范围: 104-110
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/26/11/110305

摘要

In quantum key distribution (QKD),the times of arrival of single photons are important for the keys extraction and time synchronization.The time-of-arrival (TOA) accuracy can affect the quantum bit error rate (QBER) and the final key rate.To achieve a higher accuracy and a better QKD performance,different from designing more complicated hardware circuits,we present a scheme that uses the mean TOA of M frequency-entangled photons to replace the TOA of a single photon.Moreover,to address the problem that the entanglement property is usually sensitive to the photon loss in practice,we further propose two schemes,which adopt partially entangled photons and grouping-entangled photons,respectively.In addition,we compare the effects of these three alternative schemes on the QKD performance and discuss the selection strategy for the optimal scheme in detail.The simulation results show that the proposed schemes can improve the QKD performance compared to the conventional single-photon scheme obviously,which demonstrate the effectiveness of the proposed schemes.