| （英） |
In order to determine the joint statistics of non-commuting observables experimentally, we performed sequential measurements of photon polarization with various intermediate measurement strength. Due to the statistical errors of the uncertainties in the measurement, the joint probabilities directly observed in the experiments do not correspond to the quantum joint probabilities. If we can evaluate the complete measurement errors, the intrinsic joint statistics of the initial state can be confirmed. The reconstructed joint probabilities taking measurement uncertainties into account, one of which shows negativity, correspond to the predictions of quantum theory, indicating genuine quantum correlations. |