Quantum discord of Bell cat-states under amplitude damping

TL;DR

This paper derives a closed-form expression for quantum discord in Bell cat-states under amplitude damping, analyzing their quantum correlations' evolution and comparing discord with entanglement over time.

Contribution

It provides an explicit formula for quantum discord in Bell cat-states under amplitude damping using Koashi-Winter relation, enhancing understanding of quantum correlations beyond entanglement.

Findings

Quantum discord remains robust under amplitude damping.

Entanglement, measured by concurrence, degrades faster than discord.

Quantum correlations exhibit different decay behaviors under dephasing channels.

Abstract

The evolution of pairwise quantum correlations of Bell cat-states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We used of the Koashi-Winter relation. A relation which facilitates the optimization process of the conditional entropy. We also discuss the temporal evolution of bipartite quantum correlations under a dephasing channel and compare the behaviors of quantum discord and entanglement whose properties are characterized through the concurrence.