1. Interference of two-photon transitions induced by XUV light
- Author
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M. Žitnik, A. Mihelič, K. Bučar, Š. Krušič, R. Squibb, R. Feifel, I. Ismail, P. Lablanquie, J. Palaudoux, O. Plekan, M. Di Fraia, M. Coreno, M. Manfredda, A. Simoncig, P. Rebernik Ribič, F. Sottocorona, E. Allaria, K. C. Prince, C. Callegari, F. Penent, Jozef Stefan Institute [Ljubljana] (IJS), University of Gothenburg (GU), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Théorique (LCT), Université Paris-Est Marne-la-Vallée (UPEM), Università degli studi di Trieste = University of Trieste, Istituto di Struttura della Materia (CNR-ISM), Consiglio Nazionale delle Ricerche [Roma] (CNR), Elettra Sincrotrone Trieste, and Deutsches Elektronen-Synchrotron [Hamburg] (DESY)
- Subjects
[PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Abstract
The relative phase of first ( ω 1 ) and third harmonics ( ω 3 ) extreme ultraviolet light pulses was varied to control the population of the 2 s 2 state in helium through the interference of ω 1 + ω 1 and ω 3 − ω 1 two-photon excitation paths. The population was monitored by observing the total electron yield due to the 2 s 2 autoionization decay. Maximum yield occurs when the relative phase of the two harmonics matches the phase difference of complex atomic amplitudes governing the two excitation paths. The calculated trend of atomic phase differences agrees well with the measured data in the spectral region of the resonance, provided that time-reversed − ω 1 + ω 3 path is also taken into account. These results open the way to accessing phase differences of two-photon ionization paths involving energetically distant intermediate states and to perform interferometry in the extreme ultraviolet range by monitoring final state populations.
- Published
- 2022
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