The Heisenberg Equation-Of Applied to the Free Electron, and to the Two-Level Atom Driven by a Finite - Laser Field.

S. Chaturvedi, Crispin W. Gardiner

The authors review the various models of fluctuating laser fields which have been used in the past for the treatment of resonance fluorescence of a driven two-level atom. A new treatment of this problem in the case of a partially coherent laser field is given. This method extends that of Zoller (1977, 1978) to a large ratio of atomic decay constant to driving field frequency. The method is a kind of multiple time scale method, applied to a stochastic differential equation, and is of interest in its own right. It gives a systematic expansion in powers of the ratio of the atomic decay constant to driving field frequency, and can in principle be computed to arbitrary accuracy. Computations are presented to assess the effect of the high corrections determined.

Galina A. Nemova

Abolghasem Daeichian, Bagheri, H, Mirzaee, M

On one hand a two-level atom is utilized as a qubit in quantum information technology and on the other hand the light in quantum optics is usually in the squeezed state. These reasons motivated us to explore the dynamic of a two-level atom which is driven by a field in the squeezed state. To this goal, the atom operators and the Heisenberg-Langevin equation have been employed. The master equation which reveals the dynamic of the atom has been derived using some features of the squeezed state and doing some algebra. Finally, the dynamic of the two-level atom which is driven by squeezed state field has been simulated by the derived master equation. Also, the effect of atom parameters on the dynamic has been investigated.

Harry J. Kimble, L. Mandeļ

The problem of resonance fluorescence from a two-level atom that is driven near resonance by a laser beam of finite bandwidth is tackled via the Heisenberg equations of motion, by a simple generalization of our previous treatment. It is found that the two-time intensity correlation function is again factorizable into a product of the mean light intensities at the two times, each of which is slightly modified under broad-band excitation from its value under monochromatic excitation. The spectrum of the fluorescence is affected rather more drastically, and, in general, becomes asymmetric under broad-band excitation.

Roman V. Zakharov, A. Vasil’ev, O. Tikhonova