Superbroadcasting of mixed states

Abstract

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.

4 pages, 4 figures, to appear on Phys. Rev. Lett

References in corpus (2)

• Characterizing quantum theory in terms of information-theoretic constraints
• Optimal Non-Universally Covariant Cloning

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