哈达玛映射下 genuine 多体纠缠的可压缩性
Compressibility of genuine multipartite entanglement under the Hadamard map
AI总结：
该研究以哈达玛映射为例，探讨多体纠缠超激活中的局域投影，发现存在最优拷贝数，超过后纠缠下降，区分了纠缠蒸馏与局域投影方案的差异。
AI中文摘要：
量子态研究中最反直觉的效应之一是超激活现象，即对特定任务无用的量子态，在考虑其多份拷贝时可能变得有用。在 genuine 多体纠缠中可观测到此效应，多份拷贝到单拷贝希尔伯特空间的局域投影可显著简化其超激活的实际可及性。我们以哈达玛（Hadamard）映射为例，研究多拷贝极限下此类投影的行为，并分析不同态族。结果表明，在该方案中，对固定映射存在最优拷贝数，超过该数目后所得纠缠会下降，凸显了纠缠蒸馏与局域投影方案的差异。
英文摘要：
One of the most counterintuitive effects in the examination of quantum states is the phenomenon of superactivation, which describes the fact that a quantum state, which is useless for a specific task, may become useful when one considers multiple copies of it. This effect can be observed in the case of genuine multipartite entanglement, where local projections from multiple copies to the single-copy Hilbert space could significantly simplify the practical accessibility of its superactivation. We investigate how such projections behave in the limit of many copies, using the Hadamard map as an example, and studying different state families. We show that, in this scheme, for a fixed map, an optimal number of copies exists, beyond which the obtained entanglement decreases, highlighting the differences between entanglement distillation and local projection schemes.
