Abstract
We propose a tight lower bound on the Holevo capacity of discrete Weyl channels (DWCs), which gives the exact Holevo capacity of known special cases of DWCs. Furthermore, for a physically available but otherwise unknown (channel parameters) DWC, this bound can be directly estimated by utilizing measurement configurations without entanglement and joint measurements. We show that the performance of directly estimating the proposed bound is comparable with first performing the entanglement-based optimal parameter estimation of the DWC and then computing the proposed lower bound.
- Received 24 January 2019
DOI:https://doi.org/10.1103/PhysRevA.99.042312
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