Abstract
A bipartite spin-1/2 system having the probabilities of being in the Einstein-Podolsky-Rosen (EPR) entangled state and of being orthogonal is known to admit a local realistic description if and only if (Peres criterion). We consider here a more general case where the probabilities of being in the entangled states and (Bell basis) are given, respectively, by and Following Abe and Rajagopal, we use the nonextensive entropic form which has enabled a current generalization of Boltzmann-Gibbs statistical mechanics, and determine the entire region in the space where the system is separable. For instance, in the vicinity of the EPR state, separability occurs if and only if which recovers Peres’ criterion when In the vicinity of the other three states of the Bell basis, the situation is identical. These results illustrate the computational power of this nonextensive-quantum-information procedure. In addition to this, a critical-phenomenon-like scenario emerges which enrichens the discussion.
- Received 31 July 2000
DOI:https://doi.org/10.1103/PhysRevA.63.042104
©2001 American Physical Society