WITNESSED ENTANGLEMENT
Fernando G. S. L. Brandão, Reinaldo O. Vianna · International Journal of Quantum Information · 2006
We present a new measure of entanglement for mixed states. It can be approximately computable for every state and can be used to quantify all different types of multipartite entanglement. We show that it satisfies the usual properties of a good entanglement quantifier and derive relations between it and other entanglement measures.