Entanglement combing

Phys Rev Lett. 2009 Nov 27;103(22):220501. doi: 10.1103/PhysRevLett.103.220501. Epub 2009 Nov 23.

Abstract

We show that all multipartite pure states can, under local operations, be transformed into bipartite pairwise entangled states in a "lossless fashion": An arbitrary distinguished party will keep pairwise entanglement with all other parties after the asymptotic protocol--decorrelating all other parties from each other--in a way that the degree of entanglement of this party with respect to the rest will remain entirely unchanged. The set of possible entanglement distributions of bipartite pairs is also classified. Finally, we point out several applications of this protocol as a useful primitive in quantum information theory.