Stuttgart 2012 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 18: Attosecond physics I
A 18.4: Vortrag
Dienstag, 13. März 2012, 15:15–15:30, V47.03
Correlated motion of two electrons on a 1 fs time-scale — •Christian Ott, Andreas Kaldun, Philipp Raith, Kristina Meyer, Martin Laux, Yizhu Zhang, Steffen Hagstotz, Thomas Ding, Robert Heck, and Thomas Pfeifer — Max-Planck Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg
The concerted motion of two or more electrons is at the heart of almost any chemical reaction, as molecular bonding typically involves electron correlation dynamics. We experimentally observed and analyzed the time-resolved behavior of both electrons in helium, the prototype of the three-body Coulomb problem, via the technique of transient-absorption spectroscopy, combined with attosecond-pulsed soft-x-ray light produced via high harmonic generation using few-cycle (∼7 fs) moderately intense (up to 5·1012 W/cm2) near-visible (VIS) laser pulses. Using broadband soft-x-ray light in the 60 to 70 eV energy range, we simultaneously excite up to 7 doubly-excited states of the sp2,n+ (1Po) series. A temporally resolved coupling among the states with the VIS laser pulses at various field intensities (from the perturbative to the strong-coupling regime) was observed. In particular, we discuss VIS-intensity-dependent changes (up to complete inversion) of the Fano line shape which is characteristic of these intrinsically entangled two-electron states. A laser-induced coupling among various states allows the measurement of a two-electron quantum beating on a 1 fs timescale as theoretically predicted [1].
[1] L. Argenti and E. Lindroth, Phys. Rev. Lett. 105, 053002 (2010).