发表机构
National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University（南京大学固体微结构物理国家重点实验室和物理学院，先进微结构协同创新中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究证明两量子比特态中纠缠噪声与可分离噪声代价一致，并构造量子比特-量子三态展现严格差距，通过几何与等距嵌入完成有限维多体分类。
AI 中文摘要
纠缠噪声能否比可分离噪声更有效地擦除纠缠？标准鲁棒性将附加噪声限制为可分离态；广义鲁棒性允许任意态。我们证明对于每个两量子比特态，两种代价一致，并给出一个具有严格差距的显式满秩量子比特-量子三态。部分转置下的正性（PPT）在两个维度中都刻画了可分离性，因此边界并非由PPT准则失效所致。相反，乘积向量几何允许在两量子比特对偶优化之间建立秩一桥梁，并为量子比特-量子三分离提供二维完全纠缠子空间。局部等距嵌入完成了有限维二分分类，也适用于任何固定的多分切割。结合已知的三量子比特分离，该结果对所有有限多体系统中相对于完全可分离性的普适相等性进行了分类。
英文摘要
Can entangled noise erase entanglement more efficiently than separable noise? Standard robustness restricts the added noise to separable states; generalized robustness allows any state. We prove that the two costs coincide for every two-qubit state and give an explicit full-rank qubit--qutrit state with a strict gap. Positivity under partial transpose (PPT) characterizes separability in both dimensions, so the boundary is not caused by a failure of the PPT criterion. Instead, product-vector geometry permits a rank-one bridge between the two-qubit dual optimizations and supplies a two-dimensional completely entangled subspace for the qubit--qutrit separation. Local isometric embeddings complete the finite-dimensional bipartite classification, also for any fixed multipartite cut. Combined with known three-qubit separation, the result classifies universal equality relative to full separability in all finite multipartite systems.
Comments32 pages, 4 figures
