Optimal cloning of coherent states with a linear amplifier and beam splitters

Optimal cloning of coherent states with a linear amplifier and beam splitters

Braunstein, S.L., Cerf, N.J., Iblisdir, S., van Loock, P. and Massar, S.
(2001): Physical Review Letters 86, 4938-4941. (PDF)

ABSTRACT: A transformation achieving the optimal symmetric N -> M cloning of coherent states is presented. Its implementation requires only a phase-insensitive linear amplifier and a network of beam splitters. An experimental demonstration of this continuous-variable cloner should therefore be in the scope of current technology. The link between optimal quantum cloning and optimal amplification of quantum states is also pointed out.