English

Joint Realizability Tradeoffs Bounded by Quantum Channel Incompatibility

Quantum Physics 2026-05-13 v1

Abstract

Incompatible quantum channels cannot be jointly and exactly realized, meaning that any approximate joint realization inevitably entails a tradeoff in implementation accuracy. While this notion of channel incompatibility unifies fundamental limitations such as measurement uncertainty, the no information without disturbance principle, and the no-cloning and no-broadcasting theorems, connecting these traditional relations directly to the resource-theoretic strength of incompatibility has remained elusive. In this Letter, we show that generalized robustness, a typical resource quantifier of channel incompatibility, lower bounds the total error of any approximate joint realization. Applying this result to measurement channels provides a unified, model-independent framework encompassing error-error and information-error-disturbance tradeoffs. Furthermore, our robustness-based evaluation of disturbance outperforms an algebraic bound for all POVMs in dimensions up to six.

Keywords

Cite

@article{arxiv.2605.11924,
  title  = {Joint Realizability Tradeoffs Bounded by Quantum Channel Incompatibility},
  author = {Shintaro Minagawa and Ryo Takakura and Kensei Torii},
  journal= {arXiv preprint arXiv:2605.11924},
  year   = {2026}
}

Comments

20 pages, 3 figures

R2 v1 2026-07-22T07:07:22.473Z