Chen Kai, Albeverio Sergio, Fei Shao-Ming
Institut für Angewandte Mathematik, Universität Bonn, Germany.
Phys Rev Lett. 2005 Jul 22;95(4):040504. doi: 10.1103/PhysRevLett.95.040504.
We derive an analytical lower bound for the concurrence of a bipartite quantum state in arbitrary dimension. A functional relation is established relating concurrence, the Peres-Horodecki criterion, and the realignment criterion. We demonstrate that our bound is exact for some mixed quantum states. The significance of our method is illustrated by giving a quantitative evaluation of entanglement for many bound entangled states, some of which fail to be identified by the usual concurrence estimation method.
