论文标题
掉期冒名顶替：双向量子传送及其性能
The SWAP Imposter: Bidirectional Quantum Teleportation and its Performance
论文作者
论文摘要
双向量子传送是用于交换两方之间量子信息的基本协议。具体而言，这两个人利用共享的资源状态以及本地运营和经典交流（LOCC）来交换量子状态。在这项工作中，我们简单地强调了同伴论文[Siddiqui和Wilde，Arxiv：2010.07905]的贡献。我们开发了两种不同的方法来量化非理想双向传送的误差，这是通过归一化钻石距离和通道的不忠行为来量化的。然后，我们确定两个指标给出的值在此任务上都是平等的。此外，通过放松从LOCC到完全保留部分转置阳性的操作集，我们就可以在非理想双向传送的误差上获得半限定的编程下限。我们评估了这些界限的一些关键示例 - 各向同性状态以及根本没有资源状态的范围。在这两种情况下，我们都找到了一个分析解决方案。第二个示例为经典双向传送建立了基准。我们调查的另一个例子是两个通过广义振幅阻尼通道（GADC）发送的铃铛状态。在这种情况下，我们找到了误差的分析表达式，以及与前者一致的数值解决方案。
Bidirectional quantum teleportation is a fundamental protocol for exchanging quantum information between two parties. Specifically, the two individuals make use of a shared resource state as well as local operations and classical communication (LOCC) to swap quantum states. In this work, we concisely highlight the contributions of our companion paper [Siddiqui and Wilde, arXiv:2010.07905]. We develop two different ways of quantifying the error of nonideal bidirectional teleportation by means of the normalized diamond distance and the channel infidelity. We then establish that the values given by both metrics are equal for this task. Additionally, by relaxing the set of operations allowed from LOCC to those that completely preserve the positivity of the partial transpose, we obtain semidefinite programming lower bounds on the error of nonideal bidirectional teleportation. We evaluate these bounds for some key examples -- isotropic states and when there is no resource state at all. In both cases, we find an analytical solution. The second example establishes a benchmark for classical versus quantum bidirectional teleportation. Another example that we investigate consists of two Bell states that have been sent through a generalized amplitude damping channel (GADC). For this scenario, we find an analytical expression for the error, as well as a numerical solution that agrees with the former up to numerical precision.
