Tripartite thermal correlations in an inhomogeneous spin-star system

TL;DR

This paper investigates how thermal correlations, measured by tripartite negativity, vary in an inhomogeneous spin-star system with three outer spins interacting with a central spin, highlighting differences from concurrence.

Contribution

It introduces an analysis of tripartite negativity in inhomogeneous spin-star systems, comparing it to concurrence and exploring the effects of interaction heterogeneity.

Findings

Tripartite negativity varies with interaction homogeneity.

Differences between negativity and concurrence are significant.

Inhomogeneity affects thermal correlation measures differently.

Abstract

We exploit the tripartite negativity to study the thermal correlations in a tripartite system, that is the three outer spins interacting with the central one in a spin-star system. We analyze the dependence of such correlations on the homogeneity of the interactions, starting from the case where central-outer spin interactions are identical and then focusing on the case where the three coupling constants are different. We single out some important differences between the negativity and the concurrence.