Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 5: Posters Tuesday (Photoionisation, Multi Photon Processes)
A 5.16: Poster
Dienstag, 3. April 2001, 12:30–15:00, AT3
COHERENT CONTROL OF IONIZATION PRODUCTS IN ALKALINE-EARTH ATOMS — •Mireille Aymar, Jean-Marie Lecomte, Eliane Luc-Koenig, and Martial Millet — Laboratoire Aimé Cotton CNRS II Bât. 505 91405 Orsay Cedex France
Two recent experiments in alkaline-earth atoms concerning the dynamics of coherent ionization processes and coherent control of photoionization products are interpreted. Combination of jj-coupled eigenchannel R-matrix and multichannel quantum defect theory was used to calculate the spectroscopic parameters.
The first example concerns control of photoionization yields into different ionic channels 6s1/2, 5d3/2, 5d5/2 of barium by means of two coherent interfering photoionization routes, which are both two-photon, two-colour pathways resonantly enhanced by an intermediate state [1,2].
The second example deals with wave packets in calcium created by two short coherent pulses (Ramsey interferometry) [3]. Isolated-core excitation of autoionizing Rydberg states by the two delayed pulses (0.4ps) creates two nonstationary two-electron wave packets. Variation of the delay between the coherent pulses allows to control the energy and angular distributions of electrons ejected into the 4sєℓ and 3d3/2,5/2є′ℓ′ continua.
[1] F. Wang, and D.S. Elliott, Phys. Rev. Lett. 77, 2416, 1996.
[2] E. Luc-Koenig, M. Aymar, M. Millet, J-M. Lecomte and A. Lyras, Eur. Phys. J. D 10, 205, 2000.
[3] R. van Leeuwen, M.L. Bajema and R.R. Jones, Phys. Rev. Lett. 53, 2852, 1999.