English

Convertibility of Observables

Quantum Physics 2014-08-18 v1

Abstract

Some problems of quantum information, cloning, estimation and testing of states, universal coding etc., are special example of the following `state convertibility' problem. In this paper, we consider the dual of this problem, 'observable conversion problem'. Given families of operators \{L_\theta}\}_{\theta\in\Theta} and \{M_\theta}\}_{\theta\in\Theta} , we ask whether there is a completely positive (sub) unital map which sends \{L_\theta}\} to \{M_\theta}\} for each {\theta}. We give necessary and sufficient conditions for the convertibility in some special cases.

Keywords

Cite

@article{arxiv.1408.3463,
  title  = {Convertibility of Observables},
  author = {Keiji Matsumoto},
  journal= {arXiv preprint arXiv:1408.3463},
  year   = {2014}
}
R2 v1 2026-06-22T05:29:42.114Z