Local discrimination of mixed states
Calsamiglia Costa, John (Universitat Autònoma de Barcelona. Departament de Física)
de Vicente Majúa, Julio Íñigo (Universitat Autònoma de Barcelona. Departament de Física)
Muñoz Tapia, Ramon (Universitat Autònoma de Barcelona. Departament de Física)
Bagán Capella, Emili (Universitat Autònoma de Barcelona. Departament de Física)
American Physical Society

Data:	2010
Resum:	We provide rigorous, efficiently computable and tight bounds on the average error probability of multiple-copy discrimination between qubit mixed states by local operations assisted with classical communication (LOCC). In contrast with the pure-state case, these experimentally feasible protocols perform strictly worse than the general collective ones. Our numerical results indicate that the gap between LOCC and collective error rates persists in the asymptotic limit. In order for LOCC and collective protocols to achieve the same accuracy, the former can require up to twice the number of copies of the latter. Our techniques can be used to bound the power of LOCC strategies in other similar settings, which is still one of the most elusive questions in quantum communication.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; Versió publicada
Publicat a:	Physical review letters, Vol. 105, Issue 8 (August 2010) , p. 80504, ISSN 1079-7114

DOI: 10.1103/PhysRevLett.105.080504

4 p, 160.1 KB

El registre apareix a les col·leccions:
Articles > Articles publicats