Genuine Tripartite Entanglement in a Spin-Star Network at Thermal Equilibrium

TL;DR

This paper investigates the presence of genuine tripartite entanglement in a spin-star network at thermal equilibrium using new criteria and compares these results with tripartite negativity, revealing widespread entanglement under various conditions.

Contribution

It applies recently developed multipartite entanglement criteria to a spin-star model, demonstrating their effectiveness in detecting genuine tripartite entanglement at thermal equilibrium.

Findings

Genuine tripartite entanglement exists over a wide parameter range.

New criteria effectively identify multipartite entanglement.

Comparison shows consistency with tripartite negativity results.

Abstract

In a recent paper [M. Huber {\it et al}, Phys. Rev. Lett. {\bf 104}, 210501 (2010)] new criteria to find out the presence of multipartite entanglement have been given. We exploit these tools in order to study thermal entanglement in a spin-star network made of three peripheral spins interacting with a central one. Genuine tripartite entanglement is found in a wide range of the relevant parameters. A comparison between predictions based on the new criteria and on the tripartite negativity is also given.