Volume 121, Number 5, March 2018
|Number of page(s)||6|
|Published online||03 May 2018|
Quantum correlations in multipartite quantum systems
1 Department of Theoretical Physics and Astrophysics, Tabriz University - Tabriz 51664, Iran
2 Department of Physics, Shabestar Branch, Islamic Azad University - Shabestar, Iran
3 Department of Science, Farhangian University - Tehran 19989-63341, Iran
Received: 9 November 2017
Accepted: 5 April 2018
Quantum entanglement is the most famous type of quantum correlation between elements of a quantum system that has a basic role in quantum communication protocols like quantum cryptography, teleportation and Bell inequality detection. However, it has already been shown that various applications in quantum information theory do not require entanglement. Quantum discord as a new kind of quantum correlations beyond entanglement, is the most popular candidate for general quantum correlations. In this paper, first we find the entanglement witness in a particular multipartite quantum system which consists of a N-partite system in 2n-dimensional space. Then we give an exact analytical formula for the quantum discord of this system. At the end of the paper, we investigate the additivity relation of the quantum correlation and show that this relation is satisfied for a N-partite system with 2n-dimensional space.
PACS: 03.67.-a – Quantum information / 03.65.Ta – Foundations of quantum mechanics; measurement theory / 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.)
© EPLA, 2018
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