We show that no source encoding is needed in the definition of the capacity of a quantum channel for carrying quantum information. This allows us to use the coherent information maximized over all sources and block sizes, but not encodings, to bound the quantum capacity. We perform an explicit calculation of this maximum coherent information for the quantum erasure channel and apply the bound in order find the erasure channel's capacity without relying on an unproven assumption as in an earlier paper.
Physical Review A
- Pub Date:
- November 1998
- Quantum communication;
- Information theory and communication theory;
- Quantum Physics
- 19 pages revtex with two eps figures. Submitted to Phys. Rev. A. Replaced with revised and simplified version, and improved references, etc. Why can't the last line of the comments field end with a period using this web submission form?