Düsseldorf 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

Q: Fachverband Quantenoptik und Photonik

Q 38: Quanteninformation (Konzepte I)

Q 38.4: Vortrag

Mittwoch, 21. März 2007, 12:45–13:00, 5L

Utilizing the pure state case for the unambiguous discrimination of two mixed states — •Matthias Kleinmann¹, Hermann Kampermann¹, Philippe Raynal², and Dagmar Bruß¹ — ¹Heinrich-Heine-Universität Düsseldorf, Institut für Theoretische Physik III, Universitätsstraße 1, 40225 Düsseldorf, Germany — ²Institut für Optik, Information und Photonik, Universität Erlangen-Nürnberg, Staudtstrasse 7, 91058 Erlangen, Germany

The optimal solution for the unambiguous discrimination of two pure states is known since 1995 [JS], while the mixed state case in general is still an open problem. We provide an operable criterion to test whether a given discrimination task for mixed states can be naturally decomposed into a collection of pure state tasks. Indeed, most problems in the literature prove to be of this particular structure. We furthermore investigate the optimality of measurements, which are blockwise composed from pure state measurements, as suggested in [RST]. The analysis of such measurements provides us with a new class of optimal solutions.

[JS] Phys. Lett. A 197, 83 (1995), [RST] Phys. Rev. A 68, 010301(R) (2003)