(2001):

ABSTRACT:
We propose entangled (M+1)-mode quantum states as a multiuser quantum
channel for continuous-variable communication. Arbitrary quantum states can
be sent via this channel *simultaneously* to M remote and separated
locations with equal minimum excess noise in each output mode. For a set of
coherent-state inputs, the channel realizes optimal symmetric 1 -> M cloning
at a distance ("telecloning"). It also provides the optimal cloning of
coherent states without the need of amplifying the state of interest. The
generation of the multiuser quantum channel requires no more than two
10 log_10 {(sqrt(M) - 1)/(sqrt(M) + 1)} dB squeezed states and M beam
splitters.