Positive tensor products of qubit maps and n-tensor-stable positive qubit maps

Sergey N. Filippov, Kamil Yu. Magadov

We analyze positivity of a tensor product of two linear qubit maps, ${\Phi }_1\otimes {\Phi }_2$. Positivity of maps ${\Phi }_1$ and ${\Phi }_2$ is a necessary but not a sufficient condition for positivi…