Superbroadcasting of mixed states

Giacomo Mauro D'Ariano, Chiara Macchiavello, Paolo Perinotti

Published 2005-06-29Version 1

We derive the optimal universal broadcasting for mixed states of qubits. We show that the nobroadcasting theorem cannot be generalized to more than a single input copy. Moreover, for four or more input copies it is even possible to purify the input states while broadcasting. We name such purifying broadcasting superbroadcasting.