Transport of Correlations in a Harmonic Chain

TL;DR

This paper investigates how various quantum correlations such as entanglement, steering, and discord propagate through a chain of coupled harmonic oscillators, revealing fundamental differences in their transport mechanisms under different conditions.

Contribution

It provides a comparative analysis of the transport of different quantum correlations in harmonic chains, highlighting distinctive features and the effects of thermal excitations.

Findings

Steering and discord propagate differently depending on their definitions.

Thermal excitations influence the propagation of correlations.

Open- and closed-system dynamics show contrasting behaviors.

Abstract

We study the propagation of different types of correlations through a quantum bus formed by a chain of coupled harmonic oscillators. This includes steering, entanglement, mutual information, quantum discord, and Bell-like nonlocality. The whole system consists of the quantum bus (propagation medium) and other quantum harmonic oscillators (sources and receivers of quantum correlations) weakly coupled to the chain. We are particularly interested in using the point of view of transport to spot distinctive features displayed by different kinds of correlations. We found, for instance, that there are fundamental differences in the way steering and discord propagate, depending on the way they are defined with respect to the parties involved in the initial correlated state. We analyzed both the closed- and open-system dynamics as well as the role played by thermal excitations in the propagation of the correlations.