Polytope compatibility—From quantum measurements to magic squares

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Several central problems in quantum information theory (such as measurement compatibility and quantum steering) can be rephrased as membership in the minimal matrix convex set corresponding to special polytopes (such as the hypercube or its dual). In this article, we generalize this idea and introduce the notion of polytope compatibility, by considering arbitrary polytopes. We find that semiclassical magic squares correspond to Birkhoff polytope compatibility. In general, we prove that polytope compatibility is in one-to-one correspondence with measurement compatibility, when the measurements have some elements in common and the post-processing of the joint measurement is restricted. Finally, we consider how much tuples of operators with appropriate joint numerical range have to be scaled in the worst case in order to become polytope compatible and give both analytical sufficient conditions and numerical ones based on linear programming.

OriginalsprogEngelsk
Artikelnummer122201
TidsskriftJournal of Mathematical Physics
Vol/bind64
Udgave nummer12
Antal sider33
ISSN0022-2488
DOI
StatusUdgivet - 2023

Bibliografisk note

Funding Information:
The authors would like to thank Eric Evert for discussions concerning Lemma 3.12. Moreover, the authors would like to thank the anonymous referee for Lemma 3.13 and Theorem 3.14, hereby answering a question in a previous draft of this article. I.N. was supported by the ANR projects ESQuisses, Grant Nos. ANR-20-CE47-0014-01 and STARS, ANR-20-CE40-0008, and by the PHC program Star (Applications of random matrix theory and abstract harmonic analysis to quantum information theory). S.S. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 101030346.

Publisher Copyright:
© 2023 Author(s).

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