History Matching Using Principal Component Analysis

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Genuine Four Tangle for Four Qubit States

We report a four qubit polynomial invariant that quantifies genuine four-body correlations. The four qubit invariants are obtained from transformation properties of three qubit invariants under a local unitary on the fourth qubit.Comment: 03 pages, This short communication is a contribution to the proceedings of QCMC 2012 held in Vienna, Austria, July 30th to August 3rd 201

Two-way and three-way negativities of three qubit entangled states

We propose to quantify three qubit entanglement using global negativity along with K-way negativities, where K=2 and 3. K-way partial transpose with respect to a subsystem is defined so as to shift the focus to K-way coherences of the composite system instead of K subsystems of the composite system. While genuine tripartite entanglement of three qubit composite system is generated by 3-way coherences, tripartite entanglement can be present due to 2-way coherences as well.Comment: 07 pages, 04 figures, References added, text revised and figures revise