发表机构
Indian Institute of Technology Bhubaneswar; Indian Institute of Science Education and Research Thiruvananthapuram; Stockholm University（印度技术研究所布巴内斯瓦尔分校; 印度科学教育研究特里凡得琅研究所; 斯德哥尔摩大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出拓扑无关量子优势概念，通过三方相等性任务及多面体框架，证明量子协议在任意通信拓扑下均优于经典协议，并实现信道与网络拓扑的半设备无关认证。
AI 中文摘要
量子通信在各种信息处理任务中可以超越经典通信，但这种优势通常是在固定的通信网络下建立的。在此，我们引入拓扑无关的量子优势，即量子协议在相同的通信约束下胜过所有经典协议，无论经典通信资源在各方之间如何分布或采用何种通信拓扑，即使各方可能共享无限的经典随机性。我们首先通过一个简单的三方相等性任务来展示这一现象：两个发送方接收三元经典输入，而一个无输入的接收方判断输入是否相等。随后，我们为拓扑无关通信制定了一个通用框架，并在最小三方场景中完整刻画了相应的经典关联多面体。其面不等式揭示了多个拓扑无关量子优势的实例。值得注意的是，其中一个不等式能够实现非酉量子信道的半设备无关认证，而另一个不等式则在无需任何关于网络配置的先前假设的情况下认证顺序量子网络拓扑。最后，我们将该框架扩展到四方网络，刻画了相关的经典通信结构，并识别出一个对所有允许的经典拓扑均展现量子优势的通信任务。我们的结果确立了拓扑无关性作为通信网络中一种真实且稳健的量子优势形式。
英文摘要
Quantum communication can outperform classical communication in a variety of information-processing tasks, but such advantages are typically established for a fixed communication network. Here we introduce topology-independent quantum advantage, in which a quantum protocol outperforms every classical protocol subject to the same communication constraint, irrespective of how the classical communication resource is distributed among the parties or which communication topology is employed, even when the parties may share unlimited classical randomness. We first demonstrate this phenomenon through a simple three-party equality task: two senders receive ternary classical inputs, while an input-free receiver determines whether the inputs are equal. We then formulate a general framework for topology-independent communication and completely characterize the corresponding classical correlation polytope in the minimal three-party scenario. Its facet inequalities reveal several instances of topology-independent quantum advantage. Remarkably, one of these inequalities enables the semi-device-independent certification of a nonunitary quantum channel, while another certifies a sequential quantum network topology without any prior assumption about the network configuration. Finally, we extend the framework to four-party networks, characterize the relevant classical communication structures, and identify a communication task exhibiting quantum advantages against all admissible classical topologies. Our results establish topology independence as a genuine and robust form of quantum advantage in communication networks.
Comments13 pages, 2 figures
