Stimulated Raman adiabatic passage into continuum

Abstract

We propose a technique which produces nearly complete ionization of the population of a discrete state coupled to a continuum by a two-photon transition via a lossy intermediate state whose lifetime is much shorter than the interaction duration. We show that using counterintuitively ordered pulses, as in stimulated Raman adiabatic passage (STIRAP), wherein the pulse coupling the intermediate state to the continuum precedes and partly overlaps the pulse coupling the initial and intermediate states, greatly increases the ionization signal and strongly reduces the population loss due to spontaneous emission through the lossy state. For strong spontaneous emission from that state, however, the ionization is never complete because the dark state required for STIRAP does not exist. We demonstrate that this drawback can be eliminated almost completely by creating a laser-induced continuum structure (LICS) by embedding a third discrete state into the continuum with a third control laser. This LICS introduces some coherence into the continuum, which enables a STIRAP-like population transfer into the continuum. A highly accurate analytic description is developed and numerical results are presented for Gaussian pulse shapes.

References in corpus (3)

• Photoionization of ultracold and Bose-Einstein condensed Rb atoms
• Photoionization Suppression by Continuum Coherence: Experiment and Theory
• New Window Resonances in the Potassium 3s Photoabsorption Spectrum

Cited by in corpus (7)

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• Shortcuts to adiabaticity in the presence of a continuum: applications to itinerant quantum state transfer
• Population transfer via a dissipative structural continuum
• Probing the limits of optical cycling in a predissociative diatomic molecule
• A unified approach to $\Lambda$-, $\Xi$- and $V$-type systems with one continuum
• Multilevel Laser Induced Continuum Structure
• Photoassociative cooling and trapping of a pair of interacting atoms