Abstract
We show that there are informationally complete joint measurements of two conjugated observables on a finite quantum system, meaning that they enable the identification of all quantum states from their measurement outcome statistics. We further demonstrate that it is possible to implement a joint observable as a sequential measurement. If we require minimal noise in the joint measurement, then the joint observable is unique. If is odd, then this observable is informationally complete. But if is even, then the joint observable is not informationally complete, and one has to allow more noise in order to obtain informational completeness.
- Received 22 November 2011
DOI:https://doi.org/10.1103/PhysRevA.85.012109
©2012 American Physical Society