Direct estimations of linear and nonlinear functionals of a quantum state

A K Ekert, C M Alves, D K L Oi, M Horodecki, P Horodecki, L C Kwek

Research output: Contribution to journalArticle

185 Citations (Scopus)

Abstract

We present a simple quantum network, based on the controlled-SWAP gate, that can extract certain properties of quantum states without recourse to quantum tomography. It can be used as a basic building block for direct quantum estimations of both linear and nonlinear functionals of any density operator. The network has many potential applications ranging from purity tests and eigenvalue estimations to direct characterization of some properties of quantum channels. Experimental realizations of the proposed network are within the reach of quantum technology that is currently being developed.

LanguageEnglish
Article number217901
Pages-
Number of pages4
JournalPhysical Review Letters
Volume88
Issue number21
DOIs
Publication statusPublished - 27 May 2002

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functionals
purity
eigenvalues
tomography
operators

Keywords

  • quantum states
  • quantum tomography
  • quantum estimations
  • linear
  • nonlinear

Cite this

Ekert, A. K., Alves, C. M., Oi, D. K. L., Horodecki, M., Horodecki, P., & Kwek, L. C. (2002). Direct estimations of linear and nonlinear functionals of a quantum state. Physical Review Letters, 88(21), -. [217901]. https://doi.org/10.1103/PhysRevLett.88.217901
Ekert, A K ; Alves, C M ; Oi, D K L ; Horodecki, M ; Horodecki, P ; Kwek, L C . / Direct estimations of linear and nonlinear functionals of a quantum state. In: Physical Review Letters. 2002 ; Vol. 88, No. 21. pp. -.
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Ekert, AK, Alves, CM, Oi, DKL, Horodecki, M, Horodecki, P & Kwek, LC 2002, 'Direct estimations of linear and nonlinear functionals of a quantum state' Physical Review Letters, vol. 88, no. 21, 217901, pp. -. https://doi.org/10.1103/PhysRevLett.88.217901

Direct estimations of linear and nonlinear functionals of a quantum state. / Ekert, A K ; Alves, C M ; Oi, D K L ; Horodecki, M ; Horodecki, P ; Kwek, L C .

In: Physical Review Letters, Vol. 88, No. 21, 217901, 27.05.2002, p. -.

Research output: Contribution to journalArticle

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