Bounds on multipartite concurrence and tangle

für Mathematik in den Naturwissenschaften Leipzig Bounds for multipartite concurrence

Mathematik in den Naturwissenschaften Leipzig Bounds for multipartite concurrence

Concurrence for multipartite states

We construct a generalized concurrence for general multipartite states based on local W-class and GHZ-class operators. We explicitly construct the corresponding concurrence for three-partite states. The construction of the concurrence is interesting since it is based on local operators.

Entangled three-qubit states without concurrence and three-tangle.

We provide a complete analysis of mixed three-qubit states composed of a Greenberger-Horne-Zeilinger state and a W state orthogonal to the former. We present optimal decompositions and convex roofs for the three-tangle. Further, we provide an analytical method to decide whether or not an arbitrary rank-2 state of three qubits has vanishing three-tangle. These results highlight intriguing differ...

Concurrence classes for general pure multipartite states

We propose concurrence classes for general pure multipartite states based on an orthogonal complement of a positive operator valued measure on quantum phase. In particular, we construct W m class, GHZ, and GHZ class concurrences for general pure m-partite states. We give explicit expressions for W 3 and GHZ class concurrences for general pure three-partite states and for W , GHZ, and GHZ class ...