RECONSTRUCTION OF QUANTUM STATES FROM PROPENSITIES

We focus our attention on the problem of reconstruction of density ope rators of quantum states from propensities, i.e. generalized quasiprob ability density distributions obtained by quantum filtering. We consid er propensities obtained by filtering with pure Gaussian as well as no n-Gaussian states and we present two examples: when the filter is in a squeezed coherent state and in a Fock state, respectively. We also sh ow that even in the case of filtering with statistical mixtures a comp lete reconstruction of a density operator of the measured quantum stat e can be performed.