基于指示单光子源和轨道角动量的密钥分配协议的波动分析

Fluctuation Analysis of Key Distribution Protocol Based on Heralded Single-Photon Source and Orbital Angular Momentum

针对基于指示单光子源的测量设备无关量子密钥分配协议存在基的依赖性问题和信源统计波动问题,研究了基于服从泊松分布的指示单光子源和轨道角动量的量子密钥分配协议,并进行了统计波动分析。分析了对称信道和非对称信道下,该协议的单边传输效率、密钥生成速率与安全传输距离的关系,模拟了信源的统计波动对该协议密钥生成速率和传输距离的影响。仿真结果表明,应用轨道角动量编码解决了该协议基的依赖性问题,提高了密钥生成速率和安全传输距离。统计波动对该协议密钥生成速率的影响随着传输距离的增大而扩大,在脉冲数量相同时,非对称信道下的密钥生成速率、安全传输距离大于对称信道下的。

Basis dependence and statistical fluctuation of light sources are problems for the measurement-device-independent quantum key distribution protocol based on heralded single-photon source(HSPS).To solve these problems,in this work,the quantum key distribution protocol based on HSPS in Poisson distribution and orbital angular momentum(OAM)was studied.Moreover,its statistical fluctuation was analyzed.The relationship among the transmission efficiency,key generation rate,and safe transmission distance of the protocol under symmetric and asymmetric channels was examined.Furthermore,the effect of statistical fluctuation on the key generation rate and transmission distance was simulated.Simulation results show that the problem of basis dependence is solved by OAM coding,and the key generation rate and transmission distance of the protocol are improved.The effect of statistical fluctuation on the key generation rate of the protocol increases with the transmission distance.For the same number of pulses,the key generation rate and safe transmission distance under the asymmetric channel are greater than those under the symmetric channel.