Asymptotic problems for wave-particle interactions: quantum and classical models
Résumé
This paper is devoted to the asymptotic analysis of both quantum and classical models which describe the evolution of electrons subject to the potential of an atomic crystal perturbed by the highly oscillating potential of external electromagnetic waves. We derive either Einstein rate equations or diffusion equations with respect to the energy variable, depending on whether the initial model is quantum or classical. We point out the analogies and differences in the treatment of the two models, considering successively the cases of (quasi-) periodic perturbations or random ones. We point out the different roles of the relaxation effects according to the nature of the perturbation.