Emulation Capacity between Idempotent Channels
Quantum Physics
2025-12-04 v2 Operator Algebras
Abstract
We study the optimal rates of emulation (also called interconversion) between quantum channels. When the source and the target channels are idempotent, we give a single-letter expression for the zero-error emulation capacity in terms of structural properties of the range of the two channels. This expression shows that channel emulation is not reversible for general idempotent channels. Furthermore, we establish a strong converse rate that matches with the zero-error emulation capacity when the source or the target channel is either an identity or a completely dephasing channel.
Keywords
Cite
@article{arxiv.2511.16299,
title = {Emulation Capacity between Idempotent Channels},
author = {Idris Delsol and Omar Fawzi and Li Gao and Mizanur Rahaman},
journal= {arXiv preprint arXiv:2511.16299},
year = {2025}
}
Comments
30 pages, correction of Proposition 1, results unchanged