In the paper [23] I studied a generalized 3-level Janes-Cummings model
for atoms interacting with radiation in a resonator. In such kind of models
the self-consistent field in the resonator is classical while the
atom is quantum. It was shown that if the atom levels are equidistant
and dipole transitions are possible between all levels then the
exchange of energy between the 2-mode resonant field and atoms
is chaotic. This model gives the first example of such
quantum optical system where the chaos appears in the rotating wave
approximation and can take place for arbitrary small coupling constant
between atoms and the
the resonator field. Such unusual situation appears
due to degeneracy of unperturbed system and unapplicability
of the Kolmogorov-Arnold-Moser theorem in this case.
The investigation of such kind of models but
with quantized field showed that in the chaotic regime the
statistics of levels is described by Wigner-Dyson distribution [35].