Completely positive projections and biproducts

Chris Heunen
(University of Oxford)
Aleks Kissinger
(University of Oxford)
Peter Selinger
(Dalhousie University)

The recently introduced CP*–construction unites quantum channels and classical systems, subsuming the earlier CPM–construction in categorical quantum mechanics. We compare this construction to two earlier attempts at solving this problem: freely adding biproducts to CPM, and freely splitting idempotents in CPM. The CP*–construction embeds the former, and embeds into the latter, but neither embedding is an equivalence in general.

In Bob Coecke and Matty Hoban: Proceedings of the 10th International Workshop on Quantum Physics and Logic (QPL 2013), Castelldefels (Barcelona), Spain, 17th to 19th July 2013, Electronic Proceedings in Theoretical Computer Science 171, pp. 71–83.
Published: 27th December 2014.

ArXived at: bibtex PDF
References in reconstructed bibtex, XML and HTML format (approximated).
Comments and questions to:
For website issues: