title: Interference oscillations in the angular distribution of laser-ionized electrons near ionization threshold.
abstract: We analyze the two-dimensional momentum distribution of electrons ionized by few-cycle laser pulses in the transition regime from multiphoton absorption to tunneling by solving the time-dependent Schrödinger equation and by a classical-trajectory Monte-Carlo simulation with tunneling (CTMC-T). We find a complex two-dimensional interference pattern that resembles above threshold ionization (ATI) rings at higher energies and displays Ramsauer-Townsend-type diffraction oscillations in the angular distribution near threshold. CTMC-T calculations provide a semiclassical explanation for the dominance of selected partial waves. While the present calculation pertains to hydrogen, we find surprising qualitative agreement with recent experimental data for rare gases [A. Rudenko, J. Phys. B 37, L407 (2004)].
authors.affiliation: Institute for Theoretical Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10/136, A-1040 Vienna, Austria, EU. diego@iafe.uba.ar
authors.forename: D G
authors.initials: DG
authors.lastname: Arbó
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: E
authors.initials: E
authors.lastname: Persson
authors.forename: K I
authors.initials: KI
authors.lastname: Dimitriou
authors.forename: J
authors.initials: J
authors.lastname: Burgdörfer