Contributions of different parts of spin-spin interactions to quantum correlations in a spin ring model in an external magnetic field

TL;DR

This paper analyzes how different spin-spin interaction components contribute to quantum correlations in a spin ring model with an external magnetic field, providing analytical expressions for quantum discord and studying correlation dynamics.

Contribution

It introduces an analytical approach to quantify the contributions of various spin interactions to quantum correlations in a heteronuclear spin ring model.

Findings

Quantum discord can be analytically calculated in the high temperature limit.

Different parts of the spin-spin interactions have distinct contributions to quantum correlations.

Quantum and classical correlations evolve differently with the number of spins.

Abstract

We study quantum correlations in a bipartite heteronuclear $(N-1)\times1$ system in an external magnetic field. The system consists of a spin ring with an arbitrary number $N-1$ of spins on the ring and one spin in its center. The spins on the ring are connected by secular dipole-dipole interactions and interact with the central spin through the Heisenberg $zz$-interaction. We show that the quantum discord, describing quantum correlations between the ring and the central spin, can be obtained analytically for this model in the high temperature approximation. The model allows us to find contributions of different parts of the spin-spin interactions to quantum correlations. We also investigate the evolution of quantum and classical correlations at different numbers of spins.