Entanglement entropy in the Lipkin-Meshkov-Glick model

TL;DR

This paper investigates how entanglement entropy behaves in the Lipkin-Meshkov-Glick model, revealing critical singularities and similarities to the XY chain, across various parameters and system sizes.

Contribution

It provides a detailed analysis of entanglement entropy in the LMG model, highlighting its critical behavior and comparison with known models.

Findings

Entanglement entropy shows a singularity at the critical point.

Entropy behavior is similar to the one-dimensional XY chain.

Results depend on interaction anisotropy, magnetic field, and system size.

Abstract

We analyze the entanglement entropy in the Lipkin-Meshkov-Glick model, which describes mutually interacting spins half embedded in a magnetic field. This entropy displays a singularity at the critical point that we study as a function of the interaction anisotropy, the magnetic field, and the system size. Results emerging from our analysis are surprisingly similar to those found for the one-dimensional XY chain.