Nonlinear resonant phenomena in multilevel quantum systems

Edward Shuryak

G. P. Berman, A. R. Kolovskii

Studies on the dynamics of multilevel quantum systems in a coherent radiation field are reviewed. Major attention is paid to phenomena of quantum nonlinear resonance and the interaction of two quantum nonlinear resonances, and also to the analysis of the real physical systems where these phenomena are realized.

Li Chun-Fei, Yuxiao Wang, Xueru Zhang

The intensity-dependent nonlinear refraction phenomena in a non-resonant multilevel molecular system is studied using rate equations in steady state, including saturable refraction, reverse saturable refraction, and the turnover between these two effects. The relationship between the refraction saturation and the optical Kerr effect is also discussed.

Marek Czachor

T. Okane, Robert E Scholten, Peter M. Farrell +1 more

Using a semiclassical density matrix formalism we have calculated the behavior of multilevel atoms interacting with a standing wave field, and show how complex nonlinear phenomena, including multiphoton effects, combine to produce saturation spectra as observed in experiments. We consider both 20-level sodium and 24-level rubidium models, contrasting these with a simple 2-level case. The influence of parameters such as atomic trajectory and the time the atom remains in the beam are shown to have a critical effect on the line shape of these resonances and the emission/absorption processes. Stable oscillations in the excited state populations for both the two-level and multilevel cases are shown to be limit cycles. These limit cycles undergo period doubling as the system evolves into chaos. Finally, using a Monte Carlo treatment, these processes average to produce saturated absorption spectra complete with power and Doppler broadening effects consistent with experiment.

G. P. Berman, G. M. Zaslavsky