Positive partial transpose
= Positive partial transpose
{title2=PPT}
= PPT
{c}
{synonym}
A bipartite <density operator> has positive partial transpose when $\rho^{T_B}\geq0$. Every <separable quantum state> has this property, since transposing one factor of a positive <product state> preserves positivity and the separable sum preserves it as well. The property does not depend on which local basis defines the transpose.