Universality of optimal measurements


Autoria(s): Tarrach, R., 1948-; Vidal Bonafont, Guifré
Contribuinte(s)

Universitat de Barcelona

Data(s)

04/05/2010

Resumo

We present optimal and minimal measurements on identical copies of an unknown state of a quantum bit when the quality of measuring strategies is quantified with the gain of information (Kullback-or mutual information-of probability distributions). We also show that the maximal gain of information occurs, among isotropic priors, when the state is known to be pure. Universality of optimal measurements follows from our results: using the fidelity or the gain of information, two different figures of merits, leads to exactly the same conclusions for isotropic distributions. We finally investigate the optimal capacity of N copies of an unknown state as a quantum channel of information.

Identificador

http://hdl.handle.net/2445/9562

Idioma(s)

eng

Publicador

The American Physical Society

Direitos

(c) The American Physical Society, 1999

info:eu-repo/semantics/openAccess

Palavras-Chave #Teoria quàntica #Quantum mechanics
Tipo

info:eu-repo/semantics/article