Frankfurt 2006 – scientific programme
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A: Atomphysik
A 22: Poster II: Photoionisation
A 22.11: Poster
Thursday, March 16, 2006, 16:30–18:30, Labsaal
Quantum signatures of chaos in doubly excited helium — •Y. Jiang1, R. Püttner1, D. Delande2, M. Martins3, and G. Kaindl1 — 1Freie Universität Berlin, D-14195, Berlin — 2Laboratoire Kastler-Brossel Tour 12, Universite Pierre et Marie Curie, F-75252 Paris Cedex 05, France — 3Universität Hamburg, D-22761, Hamburg
Recent studies of doubly excited helium below the ionization threshold
(SIT) I9 of He+ showed a transition to quantum chaos by analyzing the
nearest neighbor spacing distribution [1].
Present measurements in the energy region up to the SIT I15
of He+ were performed, which show excellent
agreement with state-of-the-art complex-rotation calculations.
Based on the calculations the spectral features were assigned and no
indication of Ericson fluctuations were found.
Using the theoretical results we studied the approximate quantum numbers
as well as the statistical properties of
energy levels, linewidths, and Fano parameters q.
Preliminary statistical analysis displayed
interesting precursor signatures of quantum chaos
in doubly excited helium. This
studies prove for the first time the transition region from
integrability to chaos to be much
larger than expected before since the quantum number K dissolves
rather slowly.
Reference:
[1] R. Püttner et al., Phys. Rev. Lett. 86, 3747 (2001).