As quantum technologies develop, we acquire control of an ever-growing number of quantum systems. Unfortunately, current tools to detect relevant quantum properties of quantum states, such as entanglement and Bell nonlocality, suffer from severe scalability issues and can be computed only for systems of a very modest size of around six sites. In order to address large many-body systems, we propose a renormalization-type approach based on a class of local linear transformations called connectors, which can be used to coarse grain the system in a way that preserves the property under investigation. Repeated coarse graining produces a system of manageable size, whose properties can then be explored by means of the usual techniques for small systems. In the case of a successful detection of the desired property, the method outputs a linear witness which admits an exact tensor network representation composed of connectors. We demonstrate the power of our method by certifying entanglement, Bell nonlocality, and supraquantum Bell nonlocality in systems with hundreds of sites using a normal desktop computer.

中文翻译：

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连接器张量网络：一种量子化的重新归一化类型方法

随着量子技术的发展，我们获得了越来越多的量子系统的控制权。不幸的是，当前用于检测量子态的相关量子特性（例如纠缠和Bell非局部性）的工具会遭受严重的可伸缩性问题，并且只能针对大约六个站点的非常小规模的系统进行计算。为了解决大型多体系统，我们提出了基于一类称为连接器的局部线性变换的重归一化方法，该方法可用于粗化晶粒以一种保留被调查财产的方式保存该系统。反复进行粗粒度加工后，可制得尺寸可控的系统，然后可以通过常规技术对小型系统进行探索。在成功检测到所需属性的情况下，该方法输出线性见证，该见证允许由连接器组成的精确张量网络表示。通过在使用普通台式计算机的数百个站点的系统中验证纠缠，贝尔非局部性和超量子贝尔非局部性，我们证明了我们方法的强大功能。