Pairwise quantum and classical correlations in multi-qubits states via linear relative entropy

TL;DR

This paper introduces a linear relative entropy approach to quantify pairwise quantum and classical correlations in multi-qubit states, providing explicit formulas and analyzing their additivity properties.

Contribution

It derives explicit expressions for total, quantum, and classical correlations in multi-qubit states using linear relative entropy, considering different bipartition schemes.

Findings

Explicit formulas for correlations in multi-qubit states

Analysis of additivity relations among correlations

Application to special cases of pure and mixed states

Abstract

The pairwise correlations in a multi-qubit state are quantified through a linear variant of relative entropy. In particular, we derive the explicit expressions of total, quantum and classical bipartite correlations. Two different bi-partioning schemes are considered. We discuss the derivation of closest product, quantum-classical and quantum-classical product states. We also investigate the additivity relation between the various pairwise correlations existing in pure and mixed states. As illustration, some special cases are examined.