Tomographic Discord and Quantum Correlations for System of Qubits

TL;DR

This paper introduces a new measure of quantum correlations based on the difference in quantum mutual information minimized over local unitaries, with detailed analysis on two-qubit systems and X states.

Contribution

It proposes a novel characteristic of quantum correlations using mutual information differences minimized over local unitaries, with detailed two-qubit case studies.

Findings

Quantum mutual information difference characterizes quantum correlations.

Analysis of two-qubit X states provides insights into quantum correlation measures.

The introduced measure distinguishes quantum correlations from classical ones.

Abstract

The difference of quantum mutual information for bipartite system of qubits and minimum taken with respect to local unitary transformation group is introduced as a characteristic of quantum correlations.The two qubits example (and specifically the two qubits X state) is studied in some details.