Entanglement of formation and quantum discord in multipartite j-spin coherent states

Abstract

We study the entanglement of formation and the quantum discord contained in even and odd multipartite [Formula: see text]-spin coherent states. The key element of this investigation is the fact that a single [Formula: see text]-spin coherent state is viewed as comprising [Formula: see text] qubit states. We compute the quantum correlations present in the n even and odd [Formula: see text]-spin coherent states by considering all possible bipartite splits of the multipartite system. We discuss the different bi-partition schemes of quantum systems and we examine in detail the conservation rules governing the distribution of quantum correlations between the different qubits of the multipartite system. Finally, we derive the explicit expressions of quantum correlations present in even and odd spin coherent states decomposed in four spin sub-systems. We also analyze the properties of monogamy and we show in particular that the entanglement of the formation and the quantum discord obey the relation of monogamy only for even multipartite [Formula: see text]-spin coherent states.

Intrinsic decoherence effects on correlated coherence and quantum discord in XXZ Heisenberg model

“…QD measures the difference between total correlations and classical correlations in a quantum system. However, it is a strenuous measure to calculate, and analytical expressions of QD were only obtained for two-qubit states [26,27] and quantum X-states ( see for instance the works [28][29][30][31] and references therein). Quantum correlations have been studied in many quantum systems, such as Heisenberg spin chain models (for instance, spin-1 Heisenberg chains [32], anisotropic spin-1/2 XY chain in transverse magnetic field [33]) and quantum dot systems such as two coupled double quantum dots systems [34,35] and double quantum dot system with single electron under Rashba interaction [36] ).…”