Complementarity and the algebraic structure of four-level quantum systems

Dénes Petz, András Szántó, Mihály Weiner

Research output: Contribution to journalArticle

12 Citations (Scopus)


The history of complementary observables and mutual unbiased bases is shortly reviewed. A characterization is given in terms of conditional entropy of subalgebras due to Connes and Størmer. The extension of complementarity to noncommutative subalgebras is considered as well. Possible complementary decompositions of a four-level quantum system are described and a characterization of the Bell basis is obtained: The MASA generated by the Bell basis is complementary to both M2() tensor factors.

Original languageEnglish
Pages (from-to)99-116
Number of pages18
JournalInfinite Dimensional Analysis, Quantum Probability and Related Topics
Issue number1
Publication statusPublished - Mar 1 2009


  • Bell basis
  • Complementarity
  • Conditional entropy
  • Mutually unbiased bases
  • Quantum information
  • Qubits
  • Subsystem

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Mathematical Physics
  • Applied Mathematics

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