It is shown that if a mixed state can be distilled to the singlet form it must violate partial transposition criterion [A. Peres, Phys. Rev. Lett. 76, 1413 (1996)]. It implies that there are two… Expand

An entanglement witness (EW) is an operator that allows to detect entangled states. We give necessary and sufficient conditions for such operators to be optimal, i.e. to detect entangled states in an… Expand

All our former experience with application of quantum theory seems to say that what is predicted by quantum formalism must occur in the laboratory. But the essence of quantum formalism— entanglement,… Expand

The set of shared quantum states which contain a cryptographically private key is characterized and the theory of privacy is recast as a paradigm closely related to that used in entanglement manipulation.Expand

We prove a theorem on direct relation between the optimal fidelity $f_{max}$ of teleportation and the maximal singlet fraction $F_{max}$ attainable by means of trace-preserving LQCC action (local… Expand

The quantum-information processing paradigm in which parties sharing a multipartite state distill local information is developed and it is proved that any entangled state is informationally nonlocal - i.e., has nonzero deficit, and the relation of the paradigm with measures of classical correlations introduced earlier is discussed.Expand