We discuss the abstract structure of sequential weak measurement (WM) of general observables. In all orders, the sequential WM correlations without postselection yield the corresponding correlations of the Wigner function, offering direct quantum tomography through the moments of the canonical variables. Correlations in spin-12 sequential weak measurements coincide with those in strong measurements, they are constrained kinematically, and they are equivalent with single measurements. In sequential WMs with postselection, an anomaly occurs, different from the weak value anomaly of single WMs. In particular, the spread of polarization σ as measured in double WMs of σ will diverge for certain orthogonal pre- and postselected states.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - Jul 7 2016|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics