Additivity of the entanglement of formation
Fabio Benatti, Heide Narnhofer · Physical Review A · 2001
We address the question of whether the entanglement of formation is additive over tensor products of full matrix algebras, and derive a necessary and sufficient condition for optimality of vector states. By discussing two particular cases, we suggest that such a condition may be used either to prove or to find a counterexample to additivity.