Quantum discord for multipartite coherent states interpolating between Werner and Greenberger-Horne-Zeilinger states

TL;DR

This paper investigates quantum discord in multipartite coherent states that interpolate between GHZ, Werner, and ground states, providing explicit formulas and analyzing their evolution.

Contribution

It introduces explicit expressions for quantum discord in multipartite coherent states and explores their dynamics, bridging different quantum state families.

Findings

Quantum discord is explicitly calculated for interpolating multipartite states.

The evolution of quantum correlations over time is analyzed.

Two methods for system partitioning are compared.

Abstract

The quantum discord is used as measure of quantum correlations for two families of multipartite coherent states. The first family interpolates between generalized GHZ states and generalized Werner states. The second one is an interpolation between generalized GHZ and the ground state of the multipartite quantum system. Two inequivalent ways to split the system in a pair of qubits are introduced. The explicit expressions of quantum quantum discord in multipartite coherent states are derived. Its evaluation uses the Koashi-Winter relation in optimizing the conditional entropy. The temporal evolution of quantum correlations (quantum discord and entanglement) is also discussed.