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MO: Fachverband Molekülphysik
MO 2: Elektronische Spektroskopie
MO 2.4: Vortrag
Montag, 10. März 2008, 17:15–17:30, 3F
Interference effects in the photoelectron emission of inversion symmetric molecules — •Sanja Korica1, Axel Reinköster1, Markus Braune1, Rainer Hentges1, Burkhard Langer2, and Uwe Becker1 — 1Fritz-Haber-Institut der MPG, Berlin — 2Freie Universität Berlin
Inversion symmetric molecules generate eigenstates of the parity operator. These gerade and ungerade called eigenstates reflect the phase coupling between the atomic sites of the molecule, being either positive or negative. Photoelecton emission from these molecules gives rise to oscillating partial cross sections with a phase shift of π from these symmetry eigenstates. The oscillation period depends on the bond lengths of the corresponding molecules. Cohen and Fano [1] were the first who mentioned and analysed this phenomenon of wave like behavior of photoelectron emission. Regarding the de Broglie wavelengths of the emitted photoelectron there could be less than one period up to more than ten periods of oscillation depending on the photon energy range available for experimental investigations. We show that the study of the Cohen-Fano oscillations from molecular hydrogen to the bucky ball molecule C60 covers two orders of magnitude in oscillation periods. This shows that the Cohen-Fano model of wavelike emission for two indistinguishable emitter sites is an universal model.
[1] H. D. Cohen and U. Fano, Phys. Rev. 150, 30 (1966)