Foundations of Physics

, Volume 38, Issue 12, pp 1133–1147 | Cite as

Notes on Joint Measurability of Quantum Observables

  • Teiko HeinosaariEmail author
  • Daniel Reitzner
  • Peter Stano


For sharp quantum observables the following facts hold: (i) if we have a collection of sharp observables and each pair of them is jointly measurable, then they are jointly measurable all together; (ii) if two sharp observables are jointly measurable, then their joint observable is unique and it gives the greatest lower bound for the effects corresponding to the observables; (iii) if we have two sharp observables and their every possible two outcome partitionings are jointly measurable, then the observables themselves are jointly measurable. We show that, in general, these properties do not hold. Also some possible candidates which would accompany joint measurability and generalize these apparently useful properties are discussed.


Quantum observable Joint measurement 


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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Teiko Heinosaari
    • 1
    Email author
  • Daniel Reitzner
    • 2
  • Peter Stano
    • 2
  1. 1.Department of PhysicsUniversity of TurkuTurkuFinland
  2. 2.Research Center for Quantum InformationSlovak Academy of SciencesBratislavaSlovakia

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