近日，奥地利维也纳量子科学与技术中心(VCQ)的Jörg Schmiedmayer与瑞士苏黎世联邦理工学院的Eugene Demler等人合作，成功验证了量子场模拟器中的互信息面积定律。相关研究成果已于2023年4月24日在国际知名学术期刊《自然—物理学》上发表。

该研究团队利用一维量子场论的超冷原子模拟器测量了空间扩展子系统的冯·诺伊曼熵，实验证实了间隙量子多体系统平衡态的一个基本属性——量子互信息的面积定律。此外，他们还研究了互信息与温度以及子系统之间距离的依赖关系。这项研究工作是利用超冷原子模拟器探索量子场论中纠缠的重要一步。

据了解，近年来，对熵和互信息缩放定律的理论理解已经在研究相关物质状态、量子场论和引力等领域中取得了实质性进展。然而，在量子多体系统中实验测量冯·诺伊曼熵却是一项具有挑战性的任务，因为它需要完整的密度矩阵知识，通常需要借助全态重构技术实现。

附：英文原文

Title: Verification of the area law of mutual information in a quantum field simulator

Author: Tajik, Mohammadamin, Kukuljan, Ivan, Sotiriadis, Spyros, Rauer, Bernhard, Schweigler, Thomas, Cataldini, Federica, Sabino, Joo, Mller, Frederik, Schttelkopf, Philipp, Ji, Si-Cong, Sels, Dries, Demler, Eugene, Schmiedmayer, Jörg

Issue&Volume: 2023-04-24

Abstract: The theoretical understanding of scaling laws of entropies and mutual information has led to substantial advances in the study of correlated states of matter, quantum field theory and gravity. Experimentally measuring von Neumann entropy in quantum many-body systems is challenging, as it requires complete knowledge of the density matrix, which normally requires the implementation of full state reconstruction techniques. Here we measure the von Neumann entropy of spatially extended subsystems in an ultracold atom simulator of one-dimensional quantum field theories. We experimentally verify one of the fundamental properties of equilibrium states of gapped quantum many-body systems—the area law of quantum mutual information. We also study the dependence of mutual information on temperature and on the separation between the subsystems. Our work represents a step towards employing ultracold atom simulators to probe entanglement in quantum field theories.

DOI: 10.1038/s41567-023-02027-1

Source: https://www.nature.com/articles/s41567-023-02027-1