The structure of the set of positive unital maps between M₂(ℂ) and Mₙ(ℂ) (n ≥ 3) is investigated. We proceed with the study of the "quantized" Choi matrix thus extending the methods of our previous paper [MM2]. In particular, we examine the quantized version of Størmer's extremality condition. Maps fulfilling this condition are characterized. To illustrate our approach, a careful analysis of Tang's maps is given.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-bc78-0-18,
author = {W\l adys\l aw A. Majewski and Marcin Marciniak},
title = {On the structure of positive maps between matrix algebras},
journal = {Banach Center Publications},
volume = {75},
year = {2007},
pages = {249-263},
zbl = {1140.47030},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc78-0-18}
}
Władysław A. Majewski; Marcin Marciniak. On the structure of positive maps between matrix algebras. Banach Center Publications, Tome 75 (2007) pp. 249-263. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc78-0-18/