德国帕德伯恩大学Jan Sperling研究组发现了相关自由度之间的纠缠：准粒子关联。2025年3月4日出版的《物理评论A》发表了这项成果。

纠缠的常见概念是基于分离良好的子系统。然而，由于物理限制，获得这种独立的自由度并不总是可能的。在这项工作中，研究组探讨了依赖自由度背景下的纠缠概念。作为一个物理相关的应用，他们专门研究准粒子描述的量子相关特征。

这些对于利用费米子-玻色子混合模激发的相互作用轻物质系统至关重要。通过比较独立和依赖的自由度，他们发现某些状态是非纠缠的，尽管当只关注共同、独立的描述时，它们会纠缠在一起，反之亦然。因此，在量子信息应用中轻物质链接的依赖自由度这一很少被讨论的背景下，研究组可以深入了解量子相关性的丰富性。

附：英文原文

Title: Entanglement between dependent degrees of freedom: Quasiparticle correlations

Author: Franziska Barkhausen, Laura Ares, Stefan Schumacher, Jan Sperling

Issue&Volume: 2025/03/04

Abstract: Common notions of entanglement are based on well-separated subsystems. However, obtaining such independent degrees of freedom is not always possible because of physical constraints. In this work, we explore the notion of entanglement in the context of dependent degrees of freedom. As a physically relevant application, we specifically study quantum correlation features for quasiparticle descriptions. Those are paramount for interacting light-matter systems, utilizing excitations of fermion-boson hybrid modes. By comparing independent and dependent degrees of freedom, we uncover that certain states are nonentangled although they would be entangled when only focusing on the common, independent description, and vice versa. Therefore, insight is provided into the resourcefulness of quantum correlations within the rarely discussed context of dependent degrees of freedom for light-matter links in quantum information applications.

DOI: 10.1103/PhysRevA.111.032404

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.032404