Entanglement in the Quantum Spherical Model -- a Review

TL;DR

This review discusses recent findings on entanglement measures in the Quantum Spherical Model, highlighting its role in understanding quantum criticality, long-range interactions, and finite-temperature effects in a Gaussian system.

Contribution

It provides a comprehensive overview of entanglement properties in the QSM, emphasizing physical insights over mathematical details and exploring various physical scenarios.

Findings

Entanglement entropy and negativity studied near critical points.

Long-range interactions influence entanglement behavior.

QSM serves as a versatile model for quantum critical phenomena.

Abstract

We review some recent results on entanglement in the Quantum Spherical Model (QSM). The focus lays on the physical results rather than the mathematical details. Specifically, we study several entanglement-related quantities, such asentanglement entropies, and logarithmic negativity, in the presence of quantum and classical critical points, and in magnetically ordered phases. We consider both the short as well as the long-range QSM. The study of entanglement properties of the QSM is feasible because the model is mappable to a Gaussian system in any dimension. Despite this fact the QSM is an ideal theoretical laboratory to investigate a wide variety of physical scenarios, such as non mean field criticality, the effect of long-range interactions, the interplay between finite-temperature fluctuations and genuine quantum ones.