论文标题
与不对称CHSH不平等的无关量子键分布
Device-independent quantum key distribution with asymmetric CHSH inequalities
论文作者
论文摘要
最简单的独立于设备的量子密钥分布协议是基于Clauser-Horne-Horne-Holt-Holt（CHSH）Bell不等式的基础，并且允许两个用户Alice和Bob，如果他们观察到足够强的相关性，则可以生成秘密密钥。但是，该协议之间存在不匹配，其中仅使用Alice的一个测量值来生成密钥，而CHSH表达式相对于Alice的两个测量值是对称的。因此，我们调查了使用大型钟表表达式的影响，在这些钟声中，我们对爱丽丝的测量进行了不同的权重。使用这种不对称铃铛表达式可以提高某些实验相关相关性的关键分布方案的鲁棒性。例如，对去极化通道的可耐受性错误率从7.15％提高到约7.42％。在后处理之前，将随机噪声添加到Alice的钥匙中，将阈值进一步提高到8.34％以上。我们工作的主要技术结果是在Alice的测量结果之一的von Neumann熵上紧密绑定，该结果是在我们考虑的不对称CHSH表达式家族中以量子窃听器为条件的，并允许任意噪声预处理。
The simplest device-independent quantum key distribution protocol is based on the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality and allows two users, Alice and Bob, to generate a secret key if they observe sufficiently strong correlations. There is, however, a mismatch between the protocol, in which only one of Alice's measurements is used to generate the key, and the CHSH expression, which is symmetric with respect to Alice's two measurements. We therefore investigate the impact of using an extended family of Bell expressions where we give different weights to Alice's measurements. Using this family of asymmetric Bell expressions improves the robustness of the key distribution protocol for certain experimentally-relevant correlations. As an example, the tolerable error rate improves from 7.15% to about 7.42% for the depolarising channel. Adding random noise to Alice's key before the postprocessing pushes the threshold further to more than 8.34%. The main technical result of our work is a tight bound on the von Neumann entropy of one of Alice's measurement outcomes conditioned on a quantum eavesdropper for the family of asymmetric CHSH expressions we consider and allowing for an arbitrary amount of noise preprocessing.
