Charles H. Bennett, Robin Hanson, et al.
Foundations of Physics
If two separated observers are supplied with entanglement, in the form of n pairs of particles in identical partly entangled pure states, one member of each pair being given to each observer, they can, by local actions of each observer, concentrate this entanglement into a smaller number of maximally entangled pairs of particles, for example, Einstein-Podolsky-Rosen singlets, similarly shared between the two observers. The concentration process asymptotically conserves entropy of entanglement—the von Neumann entropy of the partial density matrix seen by either observer—with the yield of singlets approaching, for large n, the base-2 entropy of entanglement of the initial partly entangled pure state. Conversely, any pure or mixed entangled state of two systems can be produced by two classically communicating separated observers, drawing on a supply of singlets as their sole source of entanglement. © 1996 The American Physical Society.
Charles H. Bennett, Robin Hanson, et al.
Foundations of Physics
Charles H. Bennett
Physica A: Statistical Mechanics and its Applications
Charles H. Bennett
Superlattices and Microstructures
Charles H. Bennett, Gilles Brassard, et al.
ISIT 1994