Distillability of Werner states using entanglement witnesses and robust semidefinite programs
Reinaldo O. Vianna, Andrew C. Doherty · Physical Review A · 2006
We use robust semidefinite programs and entanglement witnesses to study the distillability of Werner states. We perform exact numerical calculations that show two-undistillability in a region of the state space, which was previously conjectured to be undistillable. We also introduce bases that yield interesting expressions for the distillability witnesses and for a tensor product of Werner states with an arbitrary number of copies.