The notion of coexistence of quantum observables was introduced to describe the possibility of measuring two or more observables together. Here we survey the various different formalisations of this notion and their connections. We review examples illustrating the necessary degrees of unsharpness for two noncommuting observables to be jointly measurable (in one sense of the phrase). We demonstrate the possibility of measuring together (in another sense of the phrase) noncoexistent observables. This leads us to a reconsideration of the connection between joint measurability and noncommutativity of observables and of the statistical and individual aspects of quantum measurements.
|Number of pages||15|
|Publication status||Published - Oct 2010|
Bibliographical note© 2010 Springer Verlag. This is an author produced version of a paper published in Mathematica Slovaca. Uploaded in accordance with the publisher's self archiving policy.
- coexistent observables
- joint measurability
- JOINT MEASUREMENT
- UNCERTAINTY PRINCIPLE