近日，新加坡国立大学Ling, Alexander课题组研究了室温电信单光子发射器偏振编码量子密钥分配。2025年4月16日出版的《国家科学评论》杂志发表了这一最新研究成果。

单光子源（SPS）可以直接应用于量子密钥分发（QKD），因为它们允许实现规范的BB84协议。迄今为止，使用SPS的QKD实现并不普遍，因为需要低温操作，或者需要频率转换为通过电信光纤高效传输的波长。

研究组报告了使用基于GaN缺陷的室温电信SPS对偏振编码QKD的观察。在3.5公里的部署光纤上进行现场测试，损耗为4.0 dB，QBER为5.0%，安全密钥速率为585.9 bps。在32.5公里的光纤卷轴（衰减11.2 dB）中进行的进一步测试显示，偏振模色散显著降低，QBER为3.2%，安全密钥速率为50.4 bps。这些结果说明了GaN缺陷在支持偏振编码量子通信方面的潜力。

附：英文原文

Title: Polarization-encoded quantum key distribution with a room-temperature telecom single-photon emitter

Author: Xingjian, Zhang, Haoran, Zhang, Chua, Rui Ming, Eng, John, Meunier, Max, Grieve, James A, Weibo, Gao, Ling, Alexander

Issue&Volume: 2025-04-16

Abstract: Single photon sources (SPSs) are directly applicable in quantum key distribution (QKD) because they allow the implementation of the canonical BB84 protocol. To date, QKD implementations using SPS are not widespread because of the need for cryogenic operation, or frequency conversion to a wavelength efficiently transmitted over telecommunication fibers. We report an observation of polarization-encoded QKD using a room-temperature telecom SPS based on a GaN defect. A field test over 3.5 km of deployed fiber with 4.0 dB loss yielded a QBER of 5.0% and a secure key rate of 585.9 bps. Further testing in a 32.5 km fiber spool (attenuation of 11.2 dB), which exhibited substantially lower polarization mode dispersion, yielded a QBER of 3.2% and a secure key rate of 50.4 bps. These results illustrate the potential of the GaN defects for supporting polarization-encoded quantum communication.

DOI: 10.1093/nsr/nwaf147

Source: https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf147/8114807searchresult=1