Physical Review Letters

Lower Bound for Mutual Information of a Quantum Channel

Horia Scutaru

Published Jul 31, 1995• 9 citations

Abstract

We obtain a lower bound for the mutual information of a quantum transmission channel, which is perfectly analogous with Holevo's upper bound. The Uhlmann inequality for relative entropies is used, in a reverted order, for a completely positive mapping related with the mixed coherent states introduced by us seventeen years ago. Possible applications to quantum cryptography are discussed.

DOI: 10.1103/physrevlett.75.773

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