Transitions between Rydberg states in two-color corotating circularly polarized laser pulses

Abstract

We present a study of higher-order Raman ($\mathrm{\ensuremath{\Lambda}}, V$, and $S$) transitions between Rydberg states involving the absorption and emission of at least three photons in the interaction of two-color corotating circularly polarized laser pulses with the hydrogen atom. Our analysis is based on results of numerical solutions of the corresponding time-dependent Schr\"odinger equation. The results for the interaction with ($\ensuremath{\omega},2\ensuremath{\omega}$) fields show that the simultaneous interaction with both fields results in an excited state distribution over a broad range of magnetic quantum numbers. Indications of the impact of the $\mathrm{\ensuremath{\Lambda}}, V$, and $S$ transitions are found via the analysis of final distributions resulting from the preparation of the atom in specific Rydberg states. Furthermore, we show that similar mechanisms for the redistribution of population between Rydberg states are present in two-color fields with larger differences in the central frequencies, i.e., ($\ensuremath{\omega},3\ensuremath{\omega}$) and ($\ensuremath{\omega},4\ensuremath{\omega}$) fields.