Conditional entropies and their relation to entanglement criteria

Karl Gerd H. Vollbrecht, Michael M. Wolf
2002 Journal of Mathematical Physics  
We discuss conditional Renyi and Tsallis entropies for bipartite quantum systems of finite dimension. We investigate the relation between the positivity of conditional entropies and entanglement properties. It is in particular shown that any state having a negative conditional entropy with respect to any value of the entropic parameter is distillable since it violates the reduction criterion. Moreover we show that the entanglement of Werner states in odd dimensions can neither be detected by
more » ... r be detected by entropic criteria nor by any other spectral criterion.
doi:10.1063/1.1498490 fatcat:774e4kqg6zgidoiew7xo5gr2e4