Non-existence of bipartite bound entanglement with negative partial transposition
arXiv:0910.0744
Abstract
Bound entanglement with a nonpositive partial transposition (NPT) does not exist. For any NPT entangled state a distillation procedure can be based on a certain number of copies. This number is the minimal Schmidt rank of a pure state needed to witness the NPT entanglement under study.
We provide a more sophisticated proof, since we could not overcome the criticism that the used angles are not angles between vectors. Comments are welcome, 2 pages