CLASS OF FEASIBLE QUANTUM SUPERPOSITIONS OF SQUEEZED AND SUB-POISSONIAN STATES

The nature of a class of states of a given mode of a high-Q cavity, wh ich can be produced by suitable postselection experiments, is investig ated in terms: of phase-space representations of the associated densit y operators. It is shown that these states have hollow Wigner function s and can be well approximated by coherent superpositions of pairs of squeezed states in many different ways. A remarkable property of these states is that the coherence properties associated with the volcano s hape of their Wigner distributions last a fairly long rime when usual damping contributions an considered. A procedure to generate these sla tes and to analyze their sub-Poissonian components is proposed.