Interrelation between Partial Coherence and Quantum Correlations

TL;DR

This paper explores the deep connection between partial coherence and quantum correlations, especially quantum discord, and introduces new coherence measures based on these correlations and quantum Fisher information.

Contribution

It establishes a close association between partial coherence and quantum correlations, and proposes novel coherence measures derived from quantum discord and Fisher information.

Findings

Partial coherence is closely linked to quantum discord.

New coherence measures are proposed based on quantum correlations.

The study highlights the fundamental relationship between coherence and quantum correlations.

Abstract

Both coherence and entanglement stem from the superposition principle, capture quantumness of a physical system, and play a central role in quantum physics. In a multipartite quantum system, coherence and quantum correlations are closely connected. In particular, it has been established that quantum coherence of a bipartite state is an important resource for its conversion to entanglement [A. Streltsov {\it et al.}, Phys. Rev. Lett. {\bf 115}, 020403 (2015)] and to quantum discord [J. Ma {\it et al}., Phys. Rev. Lett. {\bf 116}, 160407 (2016)]. We show here that there is a very close association between partial coherence introduced by Luo and Sun [S. Luo and Y. Sun, Phys. Rev. A {\bf 96}, 022136 (2017)] and quantum correlations (quantified by quantum discord) in both directions. Furthermore, we propose families of coherence measures in terms of quantum correlations and quantum Fisher information.