利用光子轨道angular momentum实现无参考系对准的量子密钥分发

Quantum teleportation with infinite reference frame uncertainty and without prior alignment

We present two new schemes for quantum teleportation between parties whose local reference frames are misaligned by the action of a compact Lie group G. These schemes require no prior alignment of reference frames and are unaffected by arbitrary changes in reference frame alignment during execution, suiting them to situations of rapid reference frame drift. Our tight scheme yields improved purity compared to standard teleportation, in some cases substantially --- this includes the case of qubit teleportation under arbitrary SU(2) reference frame uncertainty--- while communicating no informatio…

利用量子失谐实现完全参考系无关的量子密钥分发

Realizing fully reference-frame-independent quantum key distribution by exploiting quantum discord

针对以往参考系无关量子密钥分发仅方位角无关的局限，提出奇异值与极角、方位角均无关的3×3矩阵并结合量子失谐，实现完全参考系无关的量子密钥分发，且校准密钥生成基时性能可匹配原有方案。

无非局域关联的量子逆向工程和参考系排列

Quantum reverse-engineering and reference frame alignment without non-local correlations

未知量子比特基本门的估计和参考系的对准在形式上是相同的问题。使用量子态的$N$量子比特，我们表明，这两个问题的理论精度限制，这表现为$1/N^{2}$，可以渐近地达到协变协议，利用量子相关的内部自由度，而不是更脆弱的纠缠之间的遥远的各方。这将实现密集协变编码协议的精度所需的量子比特数量减少了一半。

Alignment of reference frames and an operational interpretation for the G-asymmetry

We determine the quantum states and measurements that optimize the accessible information in a reference frame alignment protocol associated with the groups U(1), corresponding to a phase reference, and $\mathbb{Z}_M$, the cyclic group of $M$ elements. Our result provides an operational interpretation for the $G$-asymmetry which is information-theoretic and which was thus far lacking. In particular, we show that in the limit of many copies of the bounded-size quantum reference frame, the accessible information approaches the Holevo bound. This implies that the rate of alignment of reference fr…

使用密集协变编码的参考系的纠缠辅助对准

Entanglement assisted alignment of reference frames using a dense covariant coding

我们提出了一个程序的灵感来自密集编码，这使得一个高效的连续性质的信息传输。该过程要求发送者和接收者共享最大纠缠态。我们通过量子系统处理对齐参考系或三面体的具体问题。我们找到了最佳的协变测量，并计算相应的平均误差，它具有非常简单的封闭形式。简要讨论了这一过程与量子比特上的酉变换估计的联系。

Tailored bright illumination attack on distributed-phase-reference protocols

Detector control attacks on quantum key distribution systems exploit the linear mode of avalanche photodiode in single photon detectors. So far, the protocols under consideration have been the BB84 protocol and its derivatives. Here we present how bright tailored illumination exploiting the linear mode of detectors can be used to eavesdrop on distributed-phase-reference protocols, such as differential-phase-shift and coherent-one-way.