Entanglement in the classical limit: quantum correlations from classical probabilities

TL;DR

This paper explores how quantum entanglement and correlations behave as a system approaches the classical limit, showing that quantum discord can be derived from classical mutual information when effective Planck's constant is very small.

Contribution

It demonstrates that in the classical limit, quantum correlations can be understood through classical probabilities, revealing a link between quantum and classical descriptions.

Findings

Entanglement increases as the effective Planck constant approaches zero.

Quantum discord can be derived from classical mutual information in the classical limit.

Behavior is due to suppression of path interferences in the interaction.

Abstract

We investigate entanglement for a composite closed system endowed with a scaling property allowing to keep the dynamics invariant while the effective Planck constant hbar_eff of the system is varied. Entanglement increases as hbar_eff goes to 0. Moreover for sufficiently low hbar_eff the evolution of the quantum correlations, encapsulated for example in the quantum discord, can be obtained from the mutual information of the corresponding \emph{classical} system. We show this behavior is due to the local suppression of path interferences in the interaction that generates the entanglement. This behavior should be generic for quantum systems in the classical limit.