Pre- and Post-Selection Paradoxes and Contextuality in Quantum Mechanics

Authors

Matthew S. Leifer, Chapman UniversityFollow
Robert W. Spekkens, Perimeter Institute for Theoretical Physics

Document Type

Article

Publication Date

2005

Abstract

Many seemingly paradoxical effects are known in the predictions for outcomes of intermediate measurements made on pre- and post-selected quantum systems. Despite appearances, these effects do not demonstrate the impossibility of a noncontextual hidden variable theory, since an explanation in terms of measurement disturbance is possible. Nonetheless, we show that for every paradoxical effect wherein all the pre- and post-selected probabilities are 0 or 1 and the pre- and post-selected states are nonorthogonal, there is an associated proof of the impossibility of a noncontextual hidden variable theory. This proof is obtained by considering all the measurements involved in the paradoxical effect—the preselection, the post-selection, and the alternative possible intermediate measurements—as alternative possible measurements at a single time.

Comments

This article was originally published in Physical Review Letters, volume 95, in 2005. DOI: 10.1103/PhysRevLett.95.200405

Recommended Citation

Leifer, M.S., Spekkens, R.W., 2005. Pre- and Post-Selection Paradoxes and Contextuality in Quantum Mechanics. Phys. Rev. Lett. 95, 200405. doi:10.1103/PhysRevLett.95.200405

Peer Reviewed

1

Copyright

American Physical Society