Approximating incompatible von Neumann measurements simultaneously
arXiv:1005.0472 · doi:10.1103/PhysRevA.82.032328
Abstract
We study the problem of performing orthogonal qubit measurements simultaneously. Since these measurements are incompatible, one has to accept additional imprecision. An optimal joint measurement is the one with the least possible imprecision. All earlier considerations of this problem have concerned only joint measurability of observables, while in this work we also take into account conditional state transformations (i.e., instruments). We characterize the optimal joint instrument for two orthogonal von Neumann instruments as being the Luders instrument of the optimal joint observable.
9 pages, 4 figures; v2 has a more extensive introduction + other minor corrections
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Cited by in corpus (7)
- An Invitation to Quantum Incompatibility
- Multiple phase estimation for arbitrary pure states under white noise
- Measurement uncertainty relations for discrete observables: Relative entropy formulation
- Local measurement uncertainties impose a limit on non-local quantum correlations
- Incompatibility of unbiased qubit observables and Pauli channels
- Uniqueness of the joint measurement and the structure of the set of compatible quantum measurements
- Purely quantum memory in closed systems observed via imperfect measurements