W E L C O M E | learn more |
Research Center for Quantum Information
Institute of Physics, Slovak Academy of Sciences
Dúbravská cesta 9, 84511 Bratislava, Slovakia
Tel: (+421 +2) 20910701
Fax: (+421 +2) 5477-6085
| map |
N E W S | old news |
  10.11.2014 Research publication
Optimal single-shot strategies for discrimination of quantum measurements
We study discrimination of m quantum measurements in the scenario when the unknown measurement with n outcomes can be used only once. We show that ancilla-assisted discrimination procedures provide a nontrivial advantage over simple (ancilla-free) schemes for perfect distinguishability and we prove that inevitably m≤n. We derive necessary and sufficient conditions of perfect distinguishability of general binary measurements. We show that the optimization of the discrimination of projective qubit measurements and their mixtures with white noise is equivalent to the discrimination of specific quantum states. In particular, the optimal protocol for discrimination of projective qubit measurements with fixed failure rate (exploiting maximally entangled test state) is described. While minimum-error discrimination of two projective qubit measurements can be realized without any need of entanglement, we show that discrimination of three projective qubit measurements requires a bipartite probe state. Moreover, when the measurements are not projective, the non-maximally entangled test states can outperform the maximally entangled ones. Finally, we rephrase the unambiguous discrimination of measurements as quantum key distribution protocol.
by Michal Sedlák and Mário Ziman
Phys. Rev. A 90, 052312 (2014) |+++|
QUICOST (VEGA 2/0125/13), COQI (APVV-0646-10)
  13.11.2014 Popularization
Deň otvorených dverí FÚ SAV
Že neviete, čo vedci v akadémii robia? Získajte informácie z prvej ruky. Príďte sa za nami pozrieť do našej práce štvrtok 13. novembra v čase medzi 9:00-15:00. V našej seminárnej miestnosti (budova QUTE, 1. poschodie) budete môcť zúčastniť otvorenej diskusie na témy nám blízke (kvantové počítače, kryptografia, kvantová fyzika), prípadne radi odpovieme (ak budeme vedieť) na otázky. Budete si môcť pozrieť experimentálne zariadenie slúžiace pre supravodivé kvantové počítanie. V auditóriu QUTE si budete môcť vypočuť prednášky o modrých LED diódach (tohtoročná Nobelova cena) a o kvantovej teleportácii. Viac informácii o programe nájdete na týchto stránkach. Všetci ste vítaní. A možno príde aj minister ...
S E M I N A R S | more |
27/11 10:30
Pavol Neilinger (Bratislava)
Signal amplification in circuit QED

01/12 10:30
Anna Jenčová (Bratislava)
On quantum randomization criterion
V I S I T O R S | history |

26.10-07.11 Przemyslaw Sadowski
(Gliwice, Poland)






Today is 27.11.2014, You are visitor number 5523