# Dresden 2011 – wissenschaftliches Programm

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# A: Fachverband Atomphysik

## A 5: Photoionization I

### A 5.2: Hauptvortrag

### Montag, 14. März 2011, 14:30–15:00, BAR 106

**Appearance of coherent localization due to the Auger Doppler effect** — •Burkhard Langer^{1}, Rainer Hentges^{2}, Oliver Kugeler^{3}, Markus Braune^{2}, Sanja Korica^{2}, Jens Viefhaus^{2}, Daniel Rolles^{2}, Uwe Hergenhahn^{3}, Hironobu Fukuzawa^{4}, Xiaojing Liu^{4}, Yusuke Tamenori^{5}, Masamitsu Hoshino^{6}, Hiroshi Tanaka^{6}, Christophe Nicolas^{7}, Catalin Miron^{7}, Omar Al-Dossary^{8}, Kiyoshi Ueda^{4}, and Uwe Becker^{2,8} — ^{1}Freie Universität Berlin — ^{2}Fritz-Haber-Institut, Berlin — ^{3}Institut für Plasma Physik, Garching — ^{4}Tohoku University, Sendai — ^{5}Japan Synchrotron Radiation Research Institute, Hyogo — ^{6}Sophia University, Tokyo — ^{7}Synchrotron SOLEIL, France — ^{8}King Saud University, Riyadh

Homouclear diatomic molecules are inversion symmetric systems which form eigenstates of the parity operator known as *gerade* and *ungerade* states. These states are non-local superpositions of charge distributions on both nuclear sites of the molecule with a phase shift of 0 and π, respectively. Due to this intrinsic character a coherent superposition of these states generates a localized state either on the left or on the right side. Such a coherent superposition of two parity eigenstates with different symmetries occurs on top of the broad 3σ_{u} shape resonance of O_{2} because the narrow 3*s*σ_{g} Rydberg excitation is sitting just near its maximum. This gives rise to interference causing coherent localization of the emitter position of the autoionizing electron. As a result of this localization the two Doppler components of the corresponding electron have unequal intensities, the so called wrong component has half of the right component only. This unexpected experimental result could be confirmed by a numerical simulation which takes known values of the decay life time, the splitting of the excited symmetry states and the conical intersection of the corresponding potential curves into account. The result is in perfect agreement with the measurements.