Entanglement Resource Extraction in Quantum Many Body Systems

量子多体系统中的纠缠态自从有能力对其进行量化以来，一直是人们研究的热点。先前的研究已经研究了二分系统中两个单独自旋之间的纠缠;许多自旋的连续块之间的纠缠;以及空间上彼此分离的自旋块之间的纠缠。尚待详细研究的是属于同一条链的遥远自旋块之间的纠缠。这是一个有用的表征，因为它允许研究外部探针与链相互作用并相互纠缠的系统-因此可以提取自旋链中的自然纠缠作为资源。以这种方式提取纠缠比产生更可取，因为它实际上是免费的。本研究的主要目的是在各种凝聚态系统中研究这种纠缠模型，并为它的提取提供理论建议。进一步的目的是研究该方案在量子计量学中的应用，以及在研究相对论性场的纠缠结构中的应用。

Entanglement in quantum many body systems has been the subject of much research interest since the ability to quantify it first arose. Previous studies have studied the entanglement between two individual spins in a bipartite system; between contiguous blocks of many spins; and between blocks of spins spatially separated from one another. What remains to be studied in detail is the entanglement between distant blocks of spins which belong to the same chain. This is a useful characterisation to make, since it allows for the study of systems whereby external probes interact with the chain and become entangled to one another - thus the natural entanglement in the spin chain can be extracted for use as a resource. The extraction of entanglement in this way is preferable to generation, since it effectively comes for free. The primary aim of this research is to investigate such an entanglement model in various condensed matter systems, and aims to provide a theoretical proposal for its extraction. A further aim is then to investigate the application of this scheme in quantum metrology, and also in investigating the entanglement structure of relativistic fields.