发表机构
Indian Institute of Technology Palakkad; Indian Institute of Science Education and Research Pune（印度理工学院帕拉卡德分校; 印度科学教育与研究学院普纳分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过解析分解迹距离，揭示了在电荷对称性下其可有效诊断量子姆潘巴效应，而在置换对称性下因残余贡献导致不同弛豫行为。
AI 中文摘要
理解孤立量子多体系统中的对称性恢复是非平衡多体量子物理学中的一个重要问题。近期研究表明，量子姆潘巴效应可以通过纠缠不对称性来表征，其中初始对称性破缺更强的态反而恢复对称性更快。然而，目前尚不清楚传统的基于能量的度量（如迹距离）是否能够捕捉到相同的现象。我们在具有不同对称性的封闭自旋-$1/2$量子系统中，通过分析对称性破缺初始态的动力学来研究这一问题。结合数值模拟与将迹距离解析分解为对称性相干贡献和残余贡献的方法，我们确定了迹距离追踪纠缠不对称性并重现其中观察到的类姆潘巴行为的条件。对于电荷对称性，残余贡献可忽略不计，使得迹距离实际上由对称性扇区相干性主导。相比之下，对于置换对称性，显著的残余贡献导致定性不同的弛豫动力学。我们的结果确立了传统基于能量的诊断何时能够可靠地捕捉对称性恢复动力学，并阐明了纠缠不对称性与迹距离所编码的不同物理信息。
英文摘要
Understanding symmetry restoration in isolated quantum many-body systems is an important problem in nonequilibrium many-body quantum physics. Recent studies have shown that the quantum Mpemba effect can be characterized through entanglement asymmetry, where states with stronger initial symmetry breaking restore symmetry faster. However, it remains unclear whether conventional energy-based measures, such as the trace distance, capture the same phenomenon. We investigate this question in closed spin-$1/2$ quantum systems with different symmetries by analyzing the dynamics of symmetry-breaking initial states. Combining numerical simulations with an analytical decomposition of the trace distance into symmetry-coherence and residual contributions, we identify the conditions under which trace distance tracks entanglement asymmetry and reproduces the Mpemba--like behavior observed in it. For charge symmetry, the residual contribution is negligible, making the trace distance effectively governed by symmetry-sector coherences. In contrast, for permutation symmetry, a significant residual contribution leads to qualitatively different relaxation dynamics. Our results establish when conventional energy-based diagnostics reliably capture symmetry-restoration dynamics and clarify the distinct physical information encoded by entanglement asymmetry and trace distance.
Comments6 figures, 20 pages
