Wigner functions, and other quasi-probability distributions, have been an important tool in quantum optics for a long time. A quasi-probability distribution is a representation of a quantum state with certain properties. In particular it is a real-valued representation of the state. Of particular interest are states for which a Wigner function is non-negative. Spekkens showed such sets of state...

We propose a coupling scheme, where the advantages of the coherent Green’s function formalism are combined with the ability of the Wigner formalism to account for phasebreaking processes of interaction with phonons and other lattice imperfections. The Green’s function formalism is used to calculate the coherent Wigner function which provides the initial condition in an equation, from which corr...

The robust time-frequency distributions with complex-lag argument are proposed. They can provide an accurate estimation of fast varying instantaneous frequency in the presence of noise with heavy-tailed probability density function. The L-estimate form of this distribution is defined and it includes the L-estimate form of Wigner distribution as a special case. A modification for multicomponent ...