论文标题
使用中等范围的陆地自由空间QKD建模有效的BB84
Modelling efficient BB84 with applications for medium-range, terrestrial free-space QKD
论文作者
论文摘要
陆地自由空间量子键分布非常适合在密集的城市环境中部署。但是，从实验室到商业部署的过渡提出了许多重要的工程和部署问题。在这里，我们使用弱连贯的脉冲态状态协议调查了有效BB84的这些问题。我们计算不同环境条件的预期关键长度，以及由于实际考虑而限制了协议参数的范围时。特别是，我们发现，对于固定的接收器选择概率，允许发射器具有不同的基础选择概率，具体取决于不同的频道损耗和背景光级别，这是有利的。最后，我们研究了脉冲强度不确定性发现它们可以大大减少关键长度的影响。这些结果可用于确定QKD系统自由空间光学的损失预算并协助其设计。
Terrestrial free-space quantum key distribution is ideally suited for deployment in dense urban environments. The transition from laboratory to commercial deployment, however, raises a number of important engineering and deployment issues. Here, we investigate these issues for efficient BB84 using a weak coherent pulse-decoy state protocol. We calculate expected key lengths for different environmental conditions and when the scope for optimisation of protocol parameters is restricted due to practical considerations. In particular, we find that for a fixed receiver basis choice probability, it can be advantageous to allow the transmitter to have a different basis choice probability depending on varying channel loss and background light levels. Finally, we examine the effects of pulse intensity uncertainty finding that they can dramatically reduce the key length. These results can be used to determine the loss budget for the free-space optics of a QKD systems and assist in their design.
