Decision problems with quantum black boxes

Mark Hillery, Erika Andersson, Stephen M. Barnett, Daniel Oi

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We examine how to distinguish between unitary operators, when the exact form of the possible operators is not known. Instead we are supplied with 'programs' in the form of unitary transforms, which can be used as references for identifying the unknown unitary transform. All unitary transforms should be used as few times as possible. This situation is analogous to programmable state discrimination. One difference, however, is that the quantum state to which we apply the unitary transforms may be entangled, leading to a richer variety of possible strategies. By suitable selection of an input state and generalized measurement of the output state, both unambiguous and minimum-error discrimination can be achieved. Pairwise comparison of operators, comparing each transform to be identified with a program transform, is often a useful strategy. There are, however, situations in which more complicated strategies perform better. This is the case especially when the number of allowed applications of program operations is different from the number of the transforms to be identified.
LanguageEnglish
Pages244-252
Number of pages9
JournalJournal of Modern Optics
Volume57
Issue number3
Early online date26 Aug 2009
DOIs
Publication statusPublished - Jan 2010

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boxes
operators
discrimination
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Keywords

  • unambiguous discrimination
  • optimum discrimination
  • operator comparison
  • generalized measurements
  • fibre optics
  • optoelectronics
  • optics
  • optoelectronic effects
  • devices & systems

Cite this

Hillery, Mark ; Andersson, Erika ; Barnett, Stephen M. ; Oi, Daniel. / Decision problems with quantum black boxes. In: Journal of Modern Optics. 2010 ; Vol. 57, No. 3. pp. 244-252.
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Hillery, M, Andersson, E, Barnett, SM & Oi, D 2010, 'Decision problems with quantum black boxes' Journal of Modern Optics, vol. 57, no. 3, pp. 244-252. https://doi.org/10.1080/09500340903203129

Decision problems with quantum black boxes. / Hillery, Mark; Andersson, Erika; Barnett, Stephen M.; Oi, Daniel.

In: Journal of Modern Optics, Vol. 57, No. 3, 01.2010, p. 244-252.

Research output: Contribution to journalArticle

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