Resonant Interaction of Atoms with Intense Radiation Fields

O. N. Gadomskiĭ, Yu. V. Abramov

A stationary solution is obtained for the joint system of equations for atomic and field variables for two different atoms with dipole-dipole interaction in the radiation field taking into account the common radiative friction. The atoms are treated as an Lorentz oscillator with one isolated resonance. The interaction of atoms in the radiation field forms four dimensional resonances at frequencies that are substantially different from the natural frequencies of isolated atoms. Two of the four dimensional resonances are characterized by negative dispersion, and the intensity of dipole emission at these frequencies may be increased with respect to the intensity of emission at the frequencies of natural atomic resonances by a factor of about 10 12 .

Daniel F. Walls, Gerard J Milburn

Daniel F. Walls, Gerard J Milburn

Xie Li-Jun, Deng-Yu Zhang

The interaction between radiation and two-level atom was investigated by semi-classical theory and quantum theory respectively.The fidelity of the two-level atom's quantum state was written out, The influences of the radiation intensity in the case of semi-classical theory and the photon number of the radiation in the case of quantum theory on the fidelity were discussed for different atomic initial states.It is found that the fidelity of quantum state is independent of radiation intensity when the atom is initially in a superposition state and the atom interacts resonantly with the radiation field in semi-classical theory. The atom's quantum fidelity evolves periodically with time,and its frequency is modulated by radiation intensity.Furthermore,it can effectively change quantum information fidelity when the appropriate detuning is selected.

Daniel F. Walls, Gerard J Milburn

G. V. Varada, G. S. Agarwal

The two-photon absorption by a pair of two-level atoms interacting with an incident field is examined. If the laser field is weak, then the existence of the dipole-dipole interaction-induced two-photon resonance follows from the higher-order Fermi golden rule. The effects of spontaneous emission and intense fields on the dipole-dipole interaction-induced two-photon resonance is studied using density-matrix methods. The presence of an intense field is shown to result in a significant enhancement of the two-photon resonance. Numerical results for the probability of simultaneous excitation of two atoms, for the atomic correlations, and for the radiated field intensity are presented.