Uniqueness of the joint measurement and the structure of the set of compatible quantum measurements

作者:Guerini Leonardo*; Cunha Marcelo Terra
来源:Journal of Mathematical Physics, 2018, 59(4): 042106.
DOI:10.1063/1.5017699

摘要

We address the problem of characterising the compatible tuples of measurements that admit a unique joint measurement. We derive a uniqueness criterion based on the method of perturbations and apply it to show that extremal points of the set of compatible tuples admit a unique joint measurement, while all tuples that admit a unique joint measurement lie in the boundary of such a set. We also provide counter-examples showing that none of these properties are both necessary and sufficient, thus completely describing the relation between the joint measurement uniqueness and the structure of the compatible set. As a by-product of our investigations, we completely characterise the extremal and boundary points of the set of general tuples of measurements and of the subset of compatible tuples. Published by AIP Publishing.

  • 出版日期2018-4