发表机构
SISSA; INFN; University of Birmingham（国际高等研究学院; 意大利国家核物理研究所; 伯明翰大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究自由费米子链中通过局域测量产生的深层热化现象，发现测量结果在热力学极限下信息可忽略，从而形成由广义吉布斯系综决定的高斯斯克鲁奇系综，并提供了数值证据，扩展了可积系统热化的描述。
AI 中文摘要
深层热化表明，在测量子系统环境后，子系统中会出现纯态的普适系综。我们研究了自由费米子链中的这一现象，使用保持高斯性并破坏粒子数守恒的局域测量。尽管测量结果提供了有限子系统内局域守恒电荷的部分信息，但我们认为在热力学极限下，这些信息变得可忽略。这种有效的非揭示性是费米子高斯斯克鲁奇系综出现的基础，该系综由子系统的广义吉布斯系综决定。我们直接在子系统层面构建了这一普适系综，并提供数值证据表明它描述了有限温度下的晚期投影系综。我们的结果将非相互作用可积系统中的热化描述从约化密度矩阵扩展到条件纯态的普适统计。
英文摘要
Deep thermalization indicates the emergence of universal ensembles of pure states in a subsystem after measuring its environment. We investigate this phenomenon in a free-fermion chain using local measurements that preserve Gaussianity and break particle-number conservation. Although the measurement outcomes provide partial information about local conserved charges within a finite subsystem, we argue that this information becomes negligible in the thermodynamic limit. This effective non-revelation underlies the emergence of a fermionic Gaussian Scrooge ensemble, determined by the subsystem's generalized Gibbs ensemble. We construct this universal ensemble directly at the subsystem level and provide numerical evidence that it describes the late-time projected ensemble at finite temperature. Our results extend the description of thermalization in non-interacting integrable systems beyond the reduced density matrix to universal statistics of conditional pure states.
Comments28 pages, 3 figures
