Entanglement of Formation of Bipartite Quantum States
Kai Chen, Sergio A Albeverio, Shao-Ming Fei · Physical Review Letters · 2005
We give an explicit tight lower bound for the entanglement of formation for arbitrary bipartite mixed states by using the convex hull construction of a certain function. This is achieved by revealing a novel connection among the entanglement of formation, the well-known Peres-Horodecki, and realignment criteria. The bound gives a quite simple and efficiently computable way to evaluate quantitatively the degree of entanglement for any bipartite quantum state.