Quantum multimeters: A programmable state discriminator

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Authors	DUSEK Miloslav BŮŽEK Vladimír
Year of publication	2002
Type	Article in Periodical
Magazine / Source	Physical Review A
MU Faculty or unit	Faculty of Informatics
Citation
Field	Theoretical physics
Keywords	quantum information; quantum measurements; quantum processors
Description	We propose a ``programmable'' quantum device that is able to perform a specific generalized measurement from a certain set of measurements depending on a quantum state of a ``program register''. The state of the program register sets the measurement device to perform a specific measurement. In particular, we study a situation when the programmable measurement device serves for the unambiguous discrimination between non-orthogonal states. The particular pair of states that can be unambiguously discriminated is specified by the state of a program qubit. The probability of successful discrimination is not optimal for all admissible pairs. However, for some subsets it can be very close to the optimal value.
Related projects:	Informatics as the third methodology Non-sequential Models of Computing -- Quantum and Concurrent Distributed Models of Computing