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

Samuel L. Braunstein, Nicolas J. Cerf, Sofyan Iblisdir, Peter van Loock, Serge Massar

Published 2000-12-11Version 1

A transformation achieving the optimal symmetric N-to-M cloning of coherent states is presented. Its implementation only requires 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.