arXiv:2111.08675 · Physical Review Research
Atomic Floquet physics revealed by free electrons
Eduardo Arqué López, Valerio Di Giulio, F. Javier Garcı́a de Abajo
Abstract
We theoretically investigate the ability of free electrons to yield information on the nonlinear Floquet dynamics of atomic systems subject to intense external illumination. By applying a quantum-mechanical formalism to describe the atom-electron interaction under the presence of a monochromatic classical light field, we observe multiple energy features that reveal a large departure from nonillumination conditions in two- and three-level illuminated atoms, including the emergence of energy features associated with direct photon absorption and emission by the electron, as well as a varied set of Floquet resonances that strongly depend on the light intensity and frequency. Our results unveil a wealth of effects associated with the interaction between free electrons and optically driven electronic systems.