On Two-Distillable Werner States
Dragomir Ž. Djoković · Entropy · 2016
We consider bipartite mixed states ρ in a d ⊗ d quantum system. We say that ρ is PPT if its partial transpose 1 ⊗ T ( ρ ) is positive semidefinite, and otherwise ρ is NPT. The well-known Werner states are divided into three types: (a) the separable states (the same as the PPT states); (b) the one-distillable states (necessarily NPT); and (c) the NPT states which are not one-distillable. We give several different formulations and provide further evidence for the validity of the conjecture that Werner states of type (c) are not two-distillable.