Tuning Entanglement Patterns in Qubits Clusters

Abstract

<p class="MsoNormal"> <span style="font-family:Verdana;">We identify patterns of ground state entanglement, or quantum discord, in qubit clusters with three and four qubits, that are induced by varying the couplings between next-nearest neighbors in the clusters. We show that these entanglement patterns can be associated with continuous multiply connected regions in parameter space, on which entanglement quantifiers, such as the pairwise concurrence, exhibit a particular type of behavior as a function of the couplings between next-nearest neighbors in the cluster. We present the distinct patterns in diagrams in parameter space with continuous boundary lines and we associate each pattern to a specific type of pure quantum correlation. We propose this procedure as a simple method to identify useful classes of pure quantum correlations in qubit networks.</span> </p