55 research outputs found
Lippmann-Schwinger description of multiphoton ionization
We outline a formalism and develop a computational procedure to treat the
process of multiphoton ionization (MPI) of atomic targets in strong laser
fields. We treat the MPI process nonperturbatively as a decay phenomenon by
solving a coupled set of the integral Lippmann-Schwinger equations. As basic
building blocks of the theory we use a complete set of field-free atomic
states, discrete and continuous. This approach should enable us to provide both
the total and differential cross-sections of MPI of atoms with one or two
electrons. As an illustration, we apply the proposed procedure to a simple
model of MPI from a square well potential and to the hydrogen atom.Comment: 25 pages, 3 figure
Existence criteria for stabilization from the scaling behaviour of ionization probabilities
We provide a systematic derivation of the scaling behaviour of various
quantities and establish in particular the scale invariance of the ionization
probability. We discuss the gauge invariance of the scaling properties and the
manner in which they can be exploited as consistency check in explicit
analytical expressions, in perturbation theory, in the Kramers-Henneberger and
Floquet approximation, in upper and lower bound estimates and fully numerical
solutions of the time dependent Schroedinger equation. The scaling invariance
leads to a differential equation which has to be satisfied by the ionization
probability and which yields an alternative criterium for the existence of
atomic bound state stabilization.Comment: 12 pages of Latex, one figur
From the UV to the static-field limit: rates and scaling laws of intense-field ionization of helium
He in two-color AC-fields of λ1 = 248 nm and λ2 = (1/m) 248 nm, m = 2,3,4. The rate of multiphoton ionization, for weak fields, is a simple function of the phase
The continuous spectrum in the solution of the time-dependent Schrodinger equation for laser-atom interactions
He in dichromatic weak or strong ac fields of λ1 = 248 nm and λ2 = (1/m) 248 nm (m = 2,3,4)
Does a delta function atom interacting with a superstrong laser pulse exhibit stabilization?
On the violation of the exponential decay law in atomic physics: Ab initio calculation of the time-dependence of the He- 1s2p(2) P-4 non-stationary state
He in dichromatic weak or strong ac fields of lambda(1)=248 nm and lambda(2) = (1/m) 248 nm (m=2,3,4)
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