Quantum control of lossy two-level systems.

Abstract

We investigate resonance-enhanced multiphoton ionization (REMPI) using an exactly solvable two-level model. Our study focuses on the resulting population and phase dynamics, as well as the emergence and evolution of the Autler–Townes (AT) doublet structure in the photoelectron spectrum. The primary objective is to analyze the behavior of the AT doublets under variations in laser intensity, detuning, and pulse duration. The analytical results are evaluated against numerical solutions of the time-dependent Schrödinger equation (TDSE). The model successfully captures key spectral features, including AT splitting, asymmetry, peak widths and multiplicity. These findings provide insight into the control of REMPI dynamics through pulse shaping, offering a framework for tailoring spectral structures in strong-field ionization.