发表机构
The Hong Kong University of Science and Technology (Guangzhou); QudeLeap Research（香港科技大学（广州）; QudeLeap 研究）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文确定了去极化噪声下任意二分纯态最优两拷贝纯化所需预共享纠缠：一ebit最大纠缠对足够，且任何达到最优的资源态形成纠缠至少一ebit，为量子网络噪声管理提供纠缠需求基准。
AI 中文摘要
我们确定了在仅限局域操作和经典通信的条件下，空间分离的各方为实现去极化噪声下任意二分纯态的概率性两拷贝纯化的全局最优方案所需的预共享纠缠。在每个局域维度$d\ge 2$中，一个共享的最大纠缠量子比特对即已足够：局域受控交换操作能精确复现全局最优的成功变换。相反，任何达到相同基准的有限维预共享资源态，即使在正部分转置松弛下，其形成纠缠至少为一ebit。对于具有一ebit的纯资源，或包括混合态的双量子比特资源，仅当态恰好具有两个非零Schmidt权重且均等于$1/2$时，即那些局域幺正等价于最大纠缠量子比特对的态，才能达到该基准。这些发现为评估量子网络和模块化量子计算机中噪声管理的纠缠需求提供了基准。
英文摘要
We determine the preshared entanglement required for spatially separated parties, restricted to local operations and classical communication, to attain globally optimal probabilistic two-copy purification of arbitrary bipartite pure states under depolarizing noise. In every local dimension $d\ge 2$, one shared maximally entangled qubit pair suffices: local controlled-SWAP operations exactly reproduce the globally optimal successful transformation. Conversely, any finite-dimensional preshared resource state that attains the same benchmark, even under a positive-partial-transpose relaxation, must have entanglement of formation at least one ebit. For pure resources with one ebit, or for two-qubit resources including mixed states, attaining the benchmark is possible only for states with exactly two nonzero Schmidt weights, both equal to $1/2$, namely those locally unitarily equivalent to a maximally entangled qubit pair. These findings provide a benchmark for evaluating the entanglement demands of noise management in quantum networks and modular quantum computers.
Comments43 pages, 2 figures
