在具有更高形式对称性的量子场理论中违反 Eigenstate 热化假设
Osamu Fukushima1, Ryusuke Hamazaki2
1Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
Physical review letters
|October 13, 2023
概括
高形式对称性防止量子系统中的热化. 在具有离散高形式对称的系统中,非局部可观测的物质不会达到热平衡状态,而是放松到一个通用集体.
科学领域:
- 量子场理论 量子场理论
- 凝聚物质物理学 凝聚物质物理学
- 统计力学 统计力学
背景情况:
- 热化是孤立量子系统的一个基本概念,描述了平衡的方法.
- 固态热化假说 (ETH) 通过提出单个能量固态表现为典型的微规范集合来解释热化.
- 高形式对称是标准全球对称的概括,在现代物理学中起着至关重要的作用.
研究的目的:
- 研究更高形式对称对孤立量子系统的热化动态的影响.
- 通过分析和数值证明这些对称性如何阻碍热化过程.
- 为了确定受更高形式对称度影响的特定条件和类型的可观测物.
主要方法:
- 在 (d+1) 维度中使用量子场理论进行分析推导.
- 对特定可观测值的 Eigenstate热化假设 (ETH) 的分解证明.
- 在 (2+1) 维 Z2 格子尺度理论上的数值模拟.
主要成果:
- 在 (d+1) 维的p型对称性分析上导致ETH对许多 (d-p) 维可观测物的分解.
- 离散的更高形式对称性 (p≥1) 导致局部保存量缺失,导致比系统大小小的非局部可观测量缺乏热化.
- 在Z2晶格尺理论中,局部可观测物热化,但非局部磁二极管可观测物放松到与单形对称性一致的概括的吉布斯集合.
结论:
- 高形式对称性是可以防止隔离量子系统中热化的一个关键因素.
- 在存在更高形式的对称性时,ETH并不普遍适用,特别是对于非局部可观测物.
- 一般化的吉布斯集合为没有完全热化的高形式对称性系统提供了更准确的描述.
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