Joint, or simultaneous, measurements of noncommuting observables are possible within quantum mechanics, if one accepts an increase in the variances of the jointly measured observables. In this paper, we discuss joint measurements of a spin-1/2 particle along any two directions. Starting from an operational locality principle, it is shown how to obtain a bound on how sharp the joint measurement can be. We give a direct interpretation of this bound in terms of an uncertainty relation.
- quantum physics
- quantum mechanics
- measured observables
Andersson, E., Barnett, S. M., & Aspect, A. (2005). Joint measurements of spin, operational locality, and uncertainty. Physical Review A, 72(4), 042104-1-042104-8. https://doi.org/10.1103/PhysRevA.72.042104