The atomic Bloch equations driven by a quantum noise are investigated in the framework of c-number multiplicative stochastic Rabi amplitudes. It is shown that the stochastic broad-band vacuum fluctuations can be incorporated in such a way that spontaneous absorption is removed. It is shown that the multiplicative stochastic noise with no spontaneous absorption is equivalent to the quantum vacuum noise. A stochastic model of the broad-band squeezed vacuum is introduced and investigated. From such a stochastic description the fast and the slow damping rates of the Bloch polarizations are obtained. The strong-field resonance fluorescence spectrum and the steady-state atomic inversion for the stochastic model of squeezed vacuum fluctuations are derived.
We report exact results concerning the effect of dipole-dipole interaction (dispersion forces) on dynamic and steady-state characteristics of squeezing in the emitted fluorescent field from two identical coherently driven two-level atoms. The atomic system is subjected to three different damping baths in particular the normal vacuum, a broad band thermal field and a broad band squeezed vacuum. The atomic model is the Dicke model, hence possible experiments are most likely to agree with theory when performed on systems of Rydberg atoms making microwave transitions. The presence of dipole-dipole interaction can enhance squeezing for realizable values of the various parameters involved.
Le D uan Str ., V inh C ity , V ietnam ( Recei ved October 9, 2000; i n Ùnal for m Februar y 12, 2001) In this pap er we discuss the line shapes of a two -level atom in the presence of broad-band squeezed v acuum and colli sional broadenin g.W e describ e the colli sions and the squeezed v acuum using a sto chastic mo del of Rabi amplitud e Ûuctuations.F rom such a sto chastic description the fast and the slow damping rates of the Blo ch p olarizati ons are obtained.T he strong Ùeld resonance Ûuorescence spectrum in the presence of sto chastic broad-band squeezed vacuum and collisi ons is derived.