Propagation of non-classical correlations across a quantum spin chain

TL;DR

This paper investigates how non-classical quantum correlations, especially quantum discord, propagate through a spin chain, revealing that discord is more efficiently transported than entanglement under various conditions.

Contribution

It demonstrates that quantum discord outperforms entanglement in transporting quantum correlations across spin chains and highlights the influence of magnetic fields on this process.

Findings

Quantum discord is better transported than entanglement in many regimes.

Magnetic fields significantly affect the dynamics of quantum discord.

Propagation efficiency relates to single excitation transport across the chain.

Abstract

We study the transport of quantum correlations across a chain of interacting spin-1/2 particles. As a quantitative figure of merit, we choose a symmetric version of quantum discord and compare it with the transported entanglement, addressing various operating regimes of the spin medium. Discord turns out to be better transported for a wide range of working points and initial conditions of the system. We relate this behavior to the efficiency of propagation of a single excitation across the spin chain. Moreover, we point out the role played by a magnetic field in the dynamics of discord in the effective channel embodied by the chain. Our analysis can be interestingly extended to transport processes in more complex networks and the study of non-classical correlations under general quantum channels.