Discordlike correlation of bipartite coherence

TL;DR

This paper introduces a discordlike correlation of bipartite coherence, showing it aligns with quantum discord and adheres to quantum resource theory postulates, providing a new perspective on quantum correlations.

Contribution

It establishes a discordlike correlation measure of bipartite coherence and demonstrates its equivalence to quantum discord, offering a new framework consistent with quantum resource theory.

Findings

Minimum discordlike coherence coincides with quantum discord.

Discordlike coherence satisfies quantum resource theory postulates.

Relative entropy measure from discordlike coherence is a valid bipartite coherence measure.

Abstract

Quantum discord has been studied extensively as a measure of non-classical correlations which includes entanglement as a subset. Although it is well known that non-zero discord can exist without entanglement, the origin of quantum discord is not well understood as compared to entanglement, which manifests itself more simply as inseparable higher dimensional quantum superposition. In this paper we establish the discordlike correlation of bipartite coherence and then compare it to quantum discord. Consequently, we show that the minimum of the discordlike correlation of coherence coincides with the original quantum discord. This demonstrates quantum discord as the irreducible correlated bipartite coherence. In addition, the discordlike correlated coherence is shown to admit the postulates of the quantum resource theory (QRT), although the original quantum discord is not a "good" candidate under the QRT. We also find that the relative entropy measure induced from the discordlike coherence is a well-defined coherence measure for bipartite states.