Classification of entanglement and quantum phase transition in XX model

TL;DR

This paper investigates how changes in the class of ground-state entanglement relate to quantum phase transitions in the XX model, proposing a new method to classify many-body entanglement.

Contribution

It introduces a novel approach to classify entanglement in many-body states and demonstrates its application to understanding quantum phase transitions in the XX model.

Findings

QPT corresponds to a change in entanglement class

Proposed a new method for entanglement classification

Validated the approach in the XX model

Abstract

We study the relation between entanglement and quantum phase transition (QPT) from a new perspective. Motivated by one's intuition: QPT is characterized by the change of the ground-state structure, while entangled states belong to different classes have different structures, we conjecture that QPT occurs as the class of ground-state entanglement changes and prove it in XX model. Despite the classification of multipartite entanglement is yet unresolved, we proposed a new method to judge whether two many-body states belong to the same entanglement class.