  Detection power of separability criteria based on a correlation tensor is
tested within a family of generalized isotropic state in $d_1 \otimes d_2$. For
$d_1 \neq d_2$ all these criteria are weaker than positive partial
transposition (PPT) criterion. Interestingly, our analysis supports the recent
conjecture that a criterion based on symmetrically informationaly complete
positive operator-valued measure (SIC-POVMs) is stronger than realignment
criterion.
