A Lower Bound on Concurrence
Liguo Liu, Tian Chenglin, Ping‐Xing Chen, Yuan Naichang · Chinese Physics Letters · 2009
We derive an analytical lower bound on the concurrence for bipartite quantum systems with an improved computable cross norm or realignment criterion and an improved positive partial transpose criterion respectively. Furthermore we demonstrate that our bound is better than that obtained from the local uncertainty relations criterion with optimal local orthogonal observables which is known as one of the best estimations of concurrence.