星型网络关联的经典模拟成本下界
A lower bound on the classical simulation cost of star-network correlations
AI总结：
该研究针对星型网络关联的经典模拟成本，提出一项需量子系统的弃权任务，证明经典消息符号数不足时无法解决，揭示量子消息的优势及有限经典描述无法重现多量子比特联合测量统计结果
AI中文摘要：
已在多项通信任务中证实量子策略优于经典策略。我们研究星型网络中量子系统联合测量产生的关联的量子通信复杂度：星型网络中多方各向中心节点发送量子系统。我们提出一项弃权（不执行）任务，当各方发送d能级量子系统时可完美解决，若发送经典消息则需大量数据；若n方每方发送的经典消息符号数少于n^(d-1)，该任务无法确定解决。这表明此场景中量子消息相比经典消息的优势随量子系统维度及同时测量的系统数量缩放。作为应用，这说明有限大小的量子比特经典描述不足以重现足够多量子比特联合测量的统计结果。
英文摘要：
It is well established that quantum strategies outperform classical ones in several communication tasks. We study the quantum communication complexity of correlations arising from joint measurements on quantum systems distributed across a star network, where several parties each send a quantum system to a central node. We introduce an exclusion task that can be solved perfectly when each party sends a quantum $d$-level system, but would require a large classical message otherwise. In fact, the task cannot be solved with certainty if each of the $n$ parties sends a classical message with less than $n^{(d-1)}$ symbols. This implies an advantage of using quantum over classical messages in that scenario that scales with both, the dimension of the quantum system and the number of systems measured simultaneously. As an application, this shows that no finite-size classical description of a qubit suffices to reproduce the statistics of a joint measurement on sufficiently many qubits.
