2011/08/10 by Dariusz Chruściński, Chruściński, Dariusz
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Mathematical Physics (math-ph) #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum many-body systems
paper · pdf · doi:10.48550/arxiv.1108.2233
openalex publication_date 2011/08/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
It is well known that so called Breuer-Hall positive maps used in entanglement theory are optimal. We show that these maps possess much more subtle property --- they are exposed. As a byproduct it proves that a Robertson map in the algebra of 4 x 4 complex matrices is not only extreme, which was already shown by Robertson, but also exposed.