Copying Quantum States
Quantum Physics
2026-07-02 v1
Abstract
The no-broadcasting theorem in quantum information says that a set of states on a quantum system admits a common broadcasting (copying) operation if and only if their density matrices belong to a commuting family. We discuss and prove this theorem, as well as the closely related no-cloning theorem in the context of quantum probability theory, i.e. in the category of (finite dimensional) C-star-algebras with unital completely positive maps.
Cite
@article{arxiv.2607.02408,
title = {Copying Quantum States},
author = {Hans Maassen and Burkhard Kümmerer},
journal= {arXiv preprint arXiv:2607.02408},
year = {2026}
}
Comments
15 pages, appeared in the Indian Journal of Pure and Applied Mathematics (2024), a vulume dedicated to the memory of K.R. Parthasarathy