title: Optimal cloning of coherent states with a linear amplifier and beam splitters.
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.
authors.affiliation: Informatics, Bangor University, Bangor LL57 1UT, United Kingdom.
authors.forename: S L
authors.initials: SL
authors.lastname: Braunstein
authors.forename: N J
authors.initials: NJ
authors.lastname: Cerf
authors.forename: S
authors.initials: S
authors.lastname: Iblisdir
authors.forename: P
authors.initials: P
authors.lastname: van Loock
authors.forename: S
authors.initials: S
authors.lastname: Massar