Quantum cloning with nonlocal assistance: Complement of Jozsa's stronger no-cloning theorem

Koji Azuma, Masato Koashi, Hosho Katsura +1

We investigate the cases where a set $S$ of states $\{|{\psi }_i⟩\}$ cannot be cloned by itself, but is clonable with the help of another system prepared in state ${\hat{\rho }}_i$. When $S…