发表机构
University of Augsburg; Universidade Federal Fluminense（奥格斯堡大学; 弗鲁米嫩塞联邦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文证明临界量子链中结果分辨的测量后纠缠可由单个紧致共形坐标解码，揭示了指数多测量结果约化为单一自由度的Luttinger液体机制。
AI 中文摘要
对临界多体态进行局域测量会产生指数多的微观结果，每个结果定义了一个不同的条件量子态。我们探究：仅从这样一个结果中提取多少信息，才能真正预测两个未测量区域之间剩余的纠缠。我们证明，在临界量子链中，普适的结果分辨Rényi熵渐近地由直接从测量记录中提取的单个紧致共形坐标决定。紧致玻色子理论解释了这种压缩：普适熵对边界轮廓的所有空间变化分量不敏感，仅保留一个相对紧致零模。在自由费米子XX点，精确的格点恒等式揭示了该解码器背后的微观结构，而大规模逐结果计算证实了其在不同子体系几何和Rényi指数下的标度预测。相互作用XXZ链中的数值计算进一步表明，相同的微观坐标无需依赖相互作用的重新调整即可继续解码条件熵。因此，对于这一普适量，指数大的测量结果空间被约化为单个共形自由度，揭示了结果分辨测量后纠缠的新兴Luttinger液体机制。
英文摘要
A local measurement of a critical many-body state produces exponentially many microscopic outcomes, each defining a different conditioned quantum state. We ask how much information from one such outcome is actually needed to predict the entanglement that remains between two unmeasured regions. We show that, in critical quantum chains, the universal outcome-resolved Rényi entropy is asymptotically determined by a single compact conformal coordinate extracted directly from the measurement record. Compact-boson theory explains this compression: the universal entropy is insensitive to all spatially varying components of the boundary profile, retaining only a single relative compact zero mode. At the free-fermion XX point, exact lattice identities expose the microscopic structure underlying the decoder, while large-scale outcome-by-outcome calculations confirm its scaling prediction across different subsystem geometries and Rényi indices. Numerical calculations in interacting XXZ chains further show that the same microscopic coordinate continues to decode the conditional entropy without interaction-dependent retuning. Thus an exponentially large space of measurement outcomes is reduced, for this universal observable, to a single conformal degree of freedom, revealing an emergent Luttinger-liquid mechanism for outcome-resolved postmeasurement entanglement.
Comments30 pages+ 7 figures
