A family of quantum protocols
Igor Devetak, Aram W. Harrow, et al.
ISIT 2004
We exhibit quantum channels whose classical and quantum capacities, when assisted by classical feedback, exceed their unassisted classical Holevo capacity. These channels are designed to be noisy in a way that can be corrected with the help of the output and a reference system entangled with part of the input. A similar construction yields quantum channels whose classical capacity, when assisted by two-way classical communication independent of the source, exceeds their classical capacity assisted by feedback alone. We give a hierarchy of capacity inequalities and open questions. © 2006 The American Physical Society.
Igor Devetak, Aram W. Harrow, et al.
ISIT 2004
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Physical Review Letters
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Physical Review A - AMO
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