Concurrence monotones and remote entanglement distributions

Full text: The definition of concurrence is extended into a family of entanglement monotones, called concurrence monotones. The concurrence monotones have several advantages as computational manageable measures of entanglement and, in particular, they also provide bounds on quantum information tasks. As an example, we consider their applications to remote entanglement distributions (RED) such as entanglement swapping and remote preparation of bipartite entangled states (RPBES). We also present a powerful theorem which states what kind of (possibly mixed) bipartite states or distributions of bipartite states can not be remotely prepared. The theorem establishes an upper bound on the amount of G-concurrence (one member in the concurrence family) that can be created between two single-qudit nodes of quantum networks by means of tripartite RED. For pure bipartite states the bound on the G-concurrence can always be saturated by RPBES. (author)