Power symmetric matrices defned and studied by R. Sinkhorn (1981) and their
generalization by R.B. Bapat, S.K. Jain and K. Manjunatha Prasad (1999) have
been utilized to give positive block matrices with trace one possessing
positive partial transpose, the so-called PPT states. Another method to
construct such PPT states is given, it uses the form of a matrix unitarily
equivalent to its transpose obtained by S.R. Garcia and J.E. Tener (2012).
Evolvement or suppression of separability or entanglement of various levels for
a quantum dynamical semigroup of completely positive maps has been studied
using Choi-Jamiolkowsky matrix of such maps and the famous Horodecki's criteria
(1996). A Trichotomy Theorem has been proved, and examples have been given that
depend mainly on generalized Choi maps and clearly distinguish the levels of
entanglement breaking.Comment: A few corrections and changes in view of discussion with Matthias
Christand
