PIRSA:14040075

Incompatibility of observables in quantum theory and other probabilistic theories

(2014). Incompatibility of observables in quantum theory and other probabilistic theories. Perimeter Institute. https://pirsa.org/14040075

Incompatibility of observables in quantum theory and other probabilistic theories. Perimeter Institute, Apr. 01, 2014, https://pirsa.org/14040075 

          @misc{ pirsa_PIRSA:14040075,
            doi = {10.48660/14040075},
            url = {https://pirsa.org/14040075},
            author = {},
            keywords = {Quantum Foundations},
            language = {en},
            title = {Incompatibility of observables in quantum theory and other probabilistic theories},
            publisher = {Perimeter Institute},
            year = {2014},
            month = {apr},
            note = {PIRSA:14040075 see, \url{https://pirsa.org}}
          }
Talk number
PIRSA:14040075
Collection
Talk Type
Subject
Abstract
We introduce a new way of quantifying the degrees of incompatibility of two observables in a probabilistic physical theory and, based on this, a global measure of the degree of incompatibility inherent in such theories. This opens up a flexible way of comparing probabilistic theories with respect to the nonclassical feature of incompatibility. We show that quantum theory contains observables that are as incompatible as any probabilistic physical theory can have. In particular, we prove that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible. However, if one adopts a more refined measure of the degree of incompatibility, for instance, by restricting the comparison to binary observables, it turns out that there are probabilistic theories whose inherent degree of incompatibility is greater than that of quantum theory. Finally, we analyze the noise tolerance of the incompatibility of a pair of observables in a CHSH-Bell experiment.