Quantum Dissension: Generalizing Quantum Discord for Three-Qubit States

We introduce the notion of quantum dissension for a three-qubit system as a measure of quantum correlations. We use three equivalent expressions of three-variable mutual information. Their differences can be zero classically but not so in quantum domain. It generalizes the notion of quantum discord...

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Bibliographic Details
Published in:arXiv.org 2011-10
Main Authors: Chakrabarty, Indranil, Agrawal, Pankaj, Pati, Arun K
Format: Article
Language:English
Subjects:
Correlation analysis
Entangled states
Quantum theory
Qubits (quantum computing)
Subsystems
Online Access:Get full text
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Summary:We introduce the notion of quantum dissension for a three-qubit system as a measure of quantum correlations. We use three equivalent expressions of three-variable mutual information. Their differences can be zero classically but not so in quantum domain. It generalizes the notion of quantum discord to a multipartite system. There can be multiple definitions of the dissension depending on the nature of projective measurements done on the subsystems. As an illustration, we explore the consequences of these multiple definitions and compare them for three-qubit pure and mixed GHZ and W states. We find that unlike discord, dissension can be negative. This is because measurement on a subsystem may enhance the correlations in the rest of the system. This approach can pave a way to generalize the notion of quantum correlations in the multiparticle setting.
ISSN:2331-8422
DOI:10.48550/arxiv.1006.5784