Charles H. Bennett, Norman Margolus, et al.
Physical Review B
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.
Charles H. Bennett, Norman Margolus, et al.
Physical Review B
Sergey Bravyi, Libor Caha, et al.
Physical Review Letters
Charles H. Bennett
Studies in History and Philosophy of Science Part B - Studies in History and Philosophy of Modern Physics
Igor Devetak, Aram W. Harrow, et al.
Physical Review Letters