Abstract
The non-degenerate two-quanta Jaynes-Cummings model governed by Milburn equation is studied. This models the decoherence of a quantum system as it evolves through intrinsic mechanisms beyond conventional quantum mechanics governed by the Schrodinger equation. The exact solution is given. Then it is applied to investigate the effects of the intrinsic decoherence on nonclassical effects (population inversion, oscillations of the number distribution, photon antibunching effect, the cross correlation and squeezing of the cavity field). We show how the intrinsic decoherence suppresses the nonclassical behaviour in this model, for the off-resonant case.