Quantifying quantum coherence and non-classical correlation based on Hellinger distance

TL;DR

This paper introduces new measures for quantum coherence and non-classical correlation based on Hellinger distance, demonstrating their properties, relationships, and operational meanings in quantum systems.

Contribution

It proposes the first Hellinger distance-based measures for quantum coherence and non-classical correlation, with proven properties and explicit trade-off relations.

Findings

The coherence measure satisfies all criteria including strong monotonicity.

A polygamy relation for quantum coherence in multipartite systems is established.

An analytic computability of non-classical correlation measure is demonstrated.

Abstract

Quantum coherence and non-classical correlation are key features of quantum world. Quantifying coherence and non-classical correlation are two key tasks in quantum information theory. First, we present a bona fide measure of quantum coherence by utilizing the Hellinger distance. This coherence measure is proven to fulfill all the criteria of a well defined coherence measure, including the strong monotonicity in the resource theories of quantum coherence. In terms of this coherence measure, the distribution of quantum coherence in multipartite systems is studied and a corresponding polygamy relation is proposed. Its operational meanings and the relations between the generation of quantum correlations and the coherence are also investigated. Moreover, we present Hellinger distance-based measure of non-classical correlation, which not only inherits the nice properties of the Hellinger distance including contractivity, and but also shows a powerful analytic computability for a large class of quantum states. We show that there is an explicit trade-off relation satisfied by the quantum coherence and this non-classical correlation.