SN Filippov, KY Magadov - Journal of Physics A: Mathematical …, 2017 - iopscience.iop.org
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 …