Physics – Quantum Physics
Scientific paper
2008-06-17
Commun. Math. Phys. 289, 1057-1096 (2009)
Physics
Quantum Physics
31 pages
Scientific paper
The set of doubly-stochastic quantum channels and its subset of mixtures of unitaries are investigated. We provide a detailed analysis of their structure together with computable criteria for the separation of the two sets. When applied to O(d)-covariant channels this leads to a complete characterization and reveals a remarkable feature: instances of channels which are not in the convex hull of unitaries can return to it when either taking finitely many copies of them or supplementing with a completely depolarizing channel. In these scenarios this implies that a channel whose noise initially resists any environment-assisted attempt of correction can become perfectly correctable.
Mendl Christian B.
Wolf Michael M.
No associations
LandOfFree
Unital Quantum Channels - Convex Structure and Revivals of Birkhoff's Theorem does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Unital Quantum Channels - Convex Structure and Revivals of Birkhoff's Theorem, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Unital Quantum Channels - Convex Structure and Revivals of Birkhoff's Theorem will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-409145