发表机构
Ludwig Maximilian University of Munich; Max Planck Institute of Quantum Optics; Munich Center for Quantum Science and Technology (MCQST); Kyung Hee University; École Polytechnique Fédérale de Lausanne (EPFL)（慕尼黑大学; 马克斯·普朗克量子光学研究所; 慕尼黑量子科学与技术中心; 庆熙大学; 洛桑联邦理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过全局与非局域魔法度量，解析和数值研究了格点规范理论中的量子多体疤痕，发现其具有广泛的全局魔法和异常大的非局域魔法，并揭示了约束希尔伯特空间通过稳定化子不兼容Schmidt秩产生不可约非局域魔法的机制。
AI 中文摘要
混沌量子多体系统的非遍历特征通常通过局域可观测量、保真度和纠缠熵来表征。在此，我们使用非稳定化子（魔法）的全局和非局域度量，在解析和数值上研究了$(1+1)$维阿贝尔$\mathbb{Z}_2$和U$(1)$格点规范理论中接近无限温度的量子多体疤痕。我们仅从Schmidt谱推导出非局域迹距离魔法的精确闭式表达式，将局域酉变换上的优化简化为对稳定化子兼容Schmidt秩的有限最大化。我们发现，疤痕本征态尽管纠缠异常低，却可以表现出广泛的全局魔法，同时与遍历态相比保留异常大的非局域魔法。我们进一步表明，约束希尔伯特空间可以通过稳定化子不兼容的Schmidt秩产生不可约的非局域魔法，即使对于平坦的纠缠谱也是如此。
英文摘要
Nonergodic features of chaotic quantum many-body systems are commonly characterized through local observables, fidelity, and entanglement entropy. Here, using global and nonlocal measures of nonstabilizerness (magic), we study quantum many-body scars near infinite temperature in $(1+1)$-dimensional Abelian $\mathbb{Z}_2$ and U$(1)$ lattice gauge theories, both analytically and numerically. We derive an exact closed-form expression for the nonlocal trace distance magic solely from the Schmidt spectrum, reducing the optimization over local unitaries to a finite maximization over stabilizer-compatible Schmidt ranks. We find that scar eigenstates can exhibit extensive global magic despite their anomalously low entanglement, while retaining anomalously large nonlocal magic compared with ergodic states. We further show that constrained Hilbert spaces can generate irreducible nonlocal magic through stabilizer-incompatible Schmidt ranks, even for a flat entanglement spectrum.
Comments$19$ pages, $6$ figures
