München 2004 – wissenschaftliches Programm
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A: Atomphysik
A 16: Multiphotonionisation I
A 16.4: Vortrag
Donnerstag, 25. März 2004, 14:45–15:00, HS 133
Nonsequential double ionization with few-cycle laser pulses — •C. Figueira de Morisson Faria1, X. Liu2, A. Sanpera1, and M. Lewenstein1 — 1Institut für theoretische Physik, Universität Hannover, Appelstr. 2, 30167 Hannover — 2Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin
We perform theoretical investigations of non-sequential double ionization (NSDI) with linearly polarized, few-cycle pulses, taking into account electron-impact ionization both classically [1] and quantum-mechanically [2]. In the latter case, we adddress the problem within the Strong-Field Approximation using saddle-point methods. We show that the yields in the plane (p1||, p2||) of the electron momentum components parallel to the laser-field polarization are highly asymmetric, and strongly dependent on the phase difference between the carrier oscillation of a few-cycle pulse and its envelope. In fact, there exists a critical phase, around which such distributions change both their sign and shape in a radical fashion. This effect is caused by the interplay between the phase space and the tunneling probability for the first electron, and is far more extreme than those observed for other high-intensity phenomena, as for instance high-order harmonic generation and above-threshold ionization. Thus, non-sequential double ionization can be used as a tool for absolute-phase measurements which is, in principle, more efficient than existing schemes.
[1] X. Liu and C. Figueira de Morisson Faria,
physics/0310120.
C. Figueira de Morisson Faria, A. Sanpera and M. Lewenstein,
in preparation.