  We explore separability of bipartite divisions of mixed Gaussian states based
on the positivity of the Abe-Rajagopal (AR) q-conditional entropy. The AR
q-conditional entropic characterization provide more stringent restrictions on
separability (in the limit q tending to infinity) than that obtained from the
corresponding von Neumann conditional entropy (q = 1 case)--similar to the
situation in finite dimensional states. Effectiveness of this approach, in
relation to the results obtained by partial transpose criterion, is explicitly
analyzed in three illustrative examples of two-mode Gaussian states of physical
significance.
