IsAbsPPT

IsAbsPPT is a function that determines whether or not a density matrix $\rho$ is "absolutely PPT" (that is, whether or not $U\rho U^\dagger$ has positive partial transpose for all unitary matrices $U$). The conditions that determine whether or not a state is absolutely PPT were derived in.

This function returns 1 if $\rho$ is absolutely PPT, 0 if it is not absolutely PPT, and -1 if it was unable to determine whether or not $\rho$ is absolutely PPT within a reasonable amount of time.

Syntax

 * IAPPT = IsAbsPPT(RHO)
 * IAPPT = IsAbsPPT(RHO,DIM)

Argument descriptions

 * RHO: A bipartite density matrix (or any bipartite positive semidefinite operator).
 * DIM (optional, by default has both subsystems of equal dimension): A 1-by-2 vector containing the dimensions of the two subsystems that X acts on.

Examples
The maximally-mixed state is the simplest example of an absolutely PPT state: