Electron correlation vs. stabilization: A two-electron model atom in an intense laser pulse

We study numerically stabilization against ionization of a fully correlated two-electron model atom in an intense laser pulse. We concentrate on two frequency regimes: very high frequency, where the photon energy exceeds both, the ionization potential of the outer {\em and} the inner electron, and an intermediate frequency where, from a ``single active electron''-point of view the outer electron is expected to stabilize but the inner one is not. Our results reveal that correlation reduces stabilization when compared to results from single active electron-calculations. However, despite this destabilizing effect of electron correlation we still observe a decreasing ionization probability within a certain intensity domain in the high-frequency case. We compare our results from the fully correlated simulations with those from simpler, approximate models. This is useful for future work on ``real'' more-than-one electron atoms, not yet accessible to numerical {\em ab initio} methods.Comment: 8 pages, 8 figures in an extra ps-file, submitted to Phys. Rev. A, updated references and shortened introductio

Stabilization with arbitrary laser polarizations

Published versio

Seeley-Koeffizienten und Determinanten von Schroedinger-Operatoren

SIGLETIB: RN 4852 (84-48) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

High Order Harmonic Generation and Atomic Stabilization in Ultra-Intense Laser Pulses

We present results of recent numerical simulations on the non-linear response of a single-electron atom submitted to an intense laser pulse. We address both the questions of the light scattered by the atom and the possible stabilization against ionization. One of the results of our simulations is the the presence of hyper-Raman lines in the high-order harmonic spectra. We suggest that these lines could be a signature of atomic stabilization

g-Hartree ab-initio calculation of hyperfine-constants for atoms

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Exploring the Activated State of Cu/ZnO(0001)–Zn, a Model Catalyst for Methanol Synthesis

The interaction of Cu clusters with ZnO(0001)-Zn terminated crystal faces is studied after reduction at high temperatures by a combination of scanning tunneling microscopy, scanning tunneling spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy. We find that tiny amounts of Cu promote the reduction of the ZnO surface by means of triangular reconstruction. This metallization of the surface leads to a Cu-Zn alloy. The XPS results reveal that the degree of alloying depends strongly on the reduction temperature. This alloying stabilizes Zn from evaporation and H2 desorption below 500 K. On the basis of these results, we conclude that the activated catalyst surface consists of Zn-Cu alloy sites that form at 700-800 K. Moreover, the surface alloying enhances the activity of Cu/ZnO catalysts under typical methanol synthesis conditions