  The conditional version of sandwiched Tsallis relative entropy (CSTRE) is
employed to study the bipartite separability of one parameter family of N-qudit
Werner- Popescu states in their 1 : N-1 partition. For all N, the strongest
limitation on bipartite separability is realized in the limit q tending to
infinity and is found to match exactly with the separability range obtained
using an algebraic method which is both necessary and sufficient. The
theoretical superiority of using CSTRE criterion to find the bipartite
separability range over the one using Abe- Rajagopal (AR) q-conditional entropy
is illustrated by comparing the convergence of the parameter x with respect to
q, in the implicit plots of AR q-conditional entropy and CSTRE.
