强度波动下参考系无关量子密钥分发对比研究

Comparative research on reference-frame-independent quantum key distribution with intensity fluctuations

为了探究参考系无关量子密钥分发(RFI-QKD)协议下不同光源应对光源强度波动的能力差异,提出了一种在非完美光源下参考系无关协议密钥率的理论分析计算方案。考虑常见的量子通信系统参数,通过计算机仿真模拟分析对比了量子密钥分发中常用且易于获得的弱相干源(WCS)与可预报单光子源(HSPS)以及可预测相干光源(HPCS)在强度波动下的具体表现。结果表明:强度波动分析方案在参考系无关协议下具有可实现性,相比常用弱相干源,可预报单光子源和可预测相干光源在相同条件下具有更好的性能以及抵御强度波动缺陷的能力,其中可预测相干光源具有最佳密钥率和最大传输距离。

In order to explore the difference of different light sources response to light source intensity fluctuation in reference-frame-independent quantum key distribution(RFI-QKD)protocol,a theoretical analysis and calculation scheme of RFI protocol key rate under imperfect light source is proposed.Through simulation,the performance of RFI-QKD protocol with weak coherence sources(WCS)is compared with that with heralded pair-coherent sources(HPCS)and heralded single-photon sources(HSPS)under intensity fluctuations with the common quantum communication parameters.The results show that compared with WCS,HSPS and HPCS have better performance and resistance to fluctuations under the same conditions,and predictable coherent light sources show best at any condition.It indicates that the proposed intensity fluctuation analysis scheme is realizable under RFI-QKD,and the simulation results can provide a valuable reference for parameter selection and optimization of RFI-QKD experimental research.