Complete set of operational measures for the characterization of 3-qubit entanglement

Seminar date and time: 
Friday, 15 June, 2012 - 09:30
Innsbruck University
Julio de Vicente
IFAE seminar room (UAB)

Whereas bipartite entanglement of pure states is well understood, multipartite entanglement is much more subtle. In fact, our understanding of the nonlocal properties of many-body states is far from complete even in the simplest case of just three subsystems. In this talk, we characterize the entanglement contained in a pure 3–qubit state via operational entanglement measures. To this end we derive a new decomposition for arbitrary 3–qubit states, which is characterized by five parameters (up to local unitary operations). We show that these parameters are uniquely determined by bipartite entanglement measures. These quantities, which are easily computable, characterize the different forms of bipartite entanglement required to generate the state following a particular preparation procedure and, hence, have a clear physical meaning. Moreover, we show that the classification of states obtained in this way is strongly related to the one obtained when considering general local operations and classical communication.

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