Berlin 2001 – wissenschaftliches Programm
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A: Atomphysik
A 3: Multi Photon Processes
A 3.12: Vortrag
Montag, 2. April 2001, 18:30–18:45, H1058
— •Nikolai L. Manakov1, Mikhail V. Frolov1, Bogdan Borca2, and Anthony F. Starace2 — 1Department of Physics, Voronezh State University, 394693 Voronezh, Russia — 2Department of Physics and Astronomy, The University of Nebraska, Lincoln, NE 68588-0111, USA
The decrease of an atomic decay rate as the intensity of a high-frequency laser field increases [Quasistationary Stabilization (QS)] is one of the most intriguing effects in the physics of intense laser-atom interactions. We analyze this phenomenon for the exactly solvable problem of an electron in a three dimensional, short-range potential modelled by the zero-range potential. We employ the method of quasistationary quasienergy states for the calculation of total and partial (n-photon) ionization rates in an elliptically-polarized, monochromatic laser field. In contrast with predictions of a number authors on the lack of QS for ionization from a short-range potential, our analysis demonstrates the existence of a QS regime at above-threshold frequencies, but only for a limited interval of laser intensities (dependent on the frequency), whose upper limit is estimated analytically. Also, our analytical and numerical estimations show that the action of a superstrong monochromatic laser field on the weakly-bound electron is equivalent to the action of a strong static electric field. Our calculations demonstrate furthermore that for H− the stabilization may be observable using femtosecond pulses of the Nd:YAG laser with an intensity I≈ 3× 1012 W/cm2.