Cooperative transient for atoms driven by a weak coherent field

S. M. Chumakov, A. B. Klimov, J. J. Sánchez-Mondragón

I. A. Grigorenko, Boris G. Matisov

We derive the equations describing the dynamics of an ensemble of atoms with (Lambda) - scheme of levels driven by two coherent resonant fields in a case when cooperative relaxation prevails over usual incoherent spontaneous emission. We investigate numerically temporal dynamics of mean values of the collective atomic operators. When the two-photon resonance condition is fulfilled then all atoms tend to be trapped in a coherent dark state, so coherent population trapping arises in a case of cooperative decay. Most important values characterizing this phenomenon such as the width of the black line and the time of initial transient stage of evolution are evaluated.

Akundi Suguna, G. S. Agarwal

The problem of the energy absorption from a weak probe field by a system of atoms driven by a coherent laser field is considered with special reference to the collective behavior of the atomic system. The changes in the nature of the absorption spectra as the intensity of the coherent laser field is changed are examined explicitly for a system of two atoms. Cooperative effects are shown to be important for weak laser fields. For strong fields, it is shown that the absorption spectra under cooperative conditions differ from those without cooperative conditions only by a scale factor.

李一茁 Yi-zhuo LI, 孙宇杰 Yu-jie SUN, 王兆英 Zhao-ying WANG

Lorenzo M. Narducci, D.H. Feng, Robert Gilmore +1 more

We analyze the transient and steady-state properties of a model system consisting of a collection of atoms interacting cooperatively and driven by a classical external field. We obtain numerical solutions for selected atomic expectation values and suggest a steady-state scaling relation.

Jagdish Rai, Charles M. Bowden