Relativistic effects in the time evolution of an one-dimensional model atom in a laser pulse

2007 ◽  
Vol 46 (1) ◽  
pp. 15-20 ◽  
Author(s):  
M. Boca ◽  
V. Florescu
Keyword(s):  
Laser Pulse ◽  
Time Evolution ◽  
Relativistic Effects ◽  
Dimensional Model ◽  
One Dimensional ◽  
Model Atom

EFFECT OF ELECTRON CORRELATION ON THE TWO-PARTICLE DYNAMICS OF A HELIUM ATOM IN A STRONG LASER PULSE

2002 ◽  
Vol 16 (03) ◽  
pp. 415-452 ◽  
Author(s):  
NILS ERIK DAHLEN
Keyword(s):  
Laser Pulse ◽  
Helium Atom ◽  
Electron Correlation ◽  
Density Functional ◽  
Femtosecond Laser Pulses ◽  
Time Dependent ◽  
Electron Dynamics ◽  
Dimensional Model ◽  
One Dimensional ◽  
Hartree Fock

This review discusses the complicated two-electron dynamics of a helium atom in an intense, short laser pulse. A helium gas in femtosecond laser pulses at long wave lengths (λ~700 nm) and high intensities (I~1015 W /cm2) produces surprisingly high numbers of He2+ ions. These laser fields cause large and fast electron oscillations, which makes a solution of the time-dependent Schrödinger equation numerically demanding. The system can be studied using a one-dimensional model atom, which has many of the same properties as the He atom. Using the one-dimensional model, the importance of including electron correlation in a simplified description of the two-electron dynamics is demonstrated. It is shown that electron correlation becomes much less important if the laser field has a short wave length, in which case the electron oscillations are smaller and slower. The problem of including electron correlation in the calculations is discussed in terms of approaches such as time-dependent Hartree–Fock, time-dependent density functional theory and time-dependent extended Hartree–Fock. Some of the commonly used semi-classical models for describing the double-ionization process are presented.

Stark effect in a one‐dimensional model atom

1985 ◽  
Vol 53 (8) ◽  
pp. 757-760 ◽  
Author(s):  
Francisco M. Fernández ◽  
Eduardo A. Castro
Keyword(s):  
Stark Effect ◽  
Dimensional Model ◽  
One Dimensional ◽  
Model Atom

scholarly journals Propagation of an intense short laser pulse in nonuniform plasma

2001 ◽  
Vol 19 (1) ◽  
pp. 151-155
Author(s):  
H. ABBASI ◽  
H. HAKIMI PAJOUH ◽  
M.R. ROUHANI ◽  
N.L. TSINTSADZE ◽  
D.D. TSKHAKAYA
Keyword(s):  
Laser Pulse ◽  
Relativistic Effects ◽  
Intense Laser ◽  
Cold Electron ◽  
Intense Laser Pulse ◽  
Nonuniform Plasma ◽  
One Dimensional ◽  
Localized Solutions ◽  
Ion Plasma ◽  
Relativistic Equations

Propagation of an intense laser pulse in a cold electron-ion plasma is considered. Starting with the fully relativistic equations, for pancake-shaped pulses, a one-dimensional nonlinear Schrodinger equation is derived. It is shown, in quasi-stationary stage, both localized and cusp solution exist and relativistic effects cause solitons to move slower as their amplitude increases. These observations indicate particle-like behavior for localized solutions.

IONIZATION AND STABILIZATION OF A ONE-DIMENSIONAL MODEL ATOM: MAP APPROACH

1999 ◽  
Vol 13 (12) ◽  
pp. 1489-1502 ◽  
Author(s):  
TAIWANG CHENG ◽  
JIE LIU ◽  
SHIGANG CHEN
Keyword(s):  
Phase Space ◽  
Wigner Distribution ◽  
Ionization Rate ◽  
Intense Laser ◽  
Ionization Process ◽  
Space Region ◽  
Dimensional Model ◽  
One Dimensional ◽  
Quantum Version ◽  
Model Atom

In this paper, the interactions between a one-dimensional model atom and intense laser field is approximately described by a map. Both the classical version and quantum version of this map are studied. It is shown that besides classical stable islands which can bound some phase space region against ionization and then are responsible for the atomic stabilization, there is another structure in phase space, the unstable manifold, which can determine the ionization process of the system. Quantumly, the quantum quasienergy eigenstates (QE state) under absorptive boundaries, which directly related to the ionization process, are calculated. We define the QE state with smallest ionization rate as QE0 state, which represents the stabilization degree. The Wigner distribution of such QE0 state show clear fringe structures. Finally we show that the classical description and quantum description are in a correspondence manner.

scholarly journals IONIZATION IN A 1-DIMENSIONAL DIPOLE MODEL

2008 ◽  
Vol 20 (07) ◽  
pp. 835-872 ◽  
Author(s):  
O. COSTIN ◽  
J. L. LEBOWITZ ◽  
C. STUCCHIO
Keyword(s):  
Power Series ◽  
Trigonometric Polynomial ◽  
Binding Potential ◽  
Dimensional Model ◽  
Asymptotic Power ◽  
One Dimensional ◽  
Dipole Radiation ◽  
Complete Ionization ◽  
Fixed Region ◽  
Model Atom

We study the evolution of a one-dimensional model atom with δ-function binding potential, subjected to a dipole radiation field E(t)x with E(t) a 2π/ω-periodic real-valued function. We prove that when E(t) is a trigonometric polynomial, complete ionization occurs, i.e. the probability of finding the electron in any fixed region goes to zero as t → ∞. For ψ(x, t = 0) compactly supported and general periodic fields, we decompose ψ(x, t) into uniquely defined resonance terms and a remainder. Each resonance is 2π/ω periodic in time and behaves like the exponentially growing Green's function near x = ±∞. The remainder is given by an asymptotic power series in t-1/2 with coefficients varying with x.

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