Atomic distortion and ac-Stark shifts of H under extreme radiation conditions

Journal Article · Wed Nov 15 00:00:00 EST 1989 · Physical Review (Section) A: General Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevA.40.5659· OSTI ID:5245404

Pont, M ^[1]

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1. Stichting voor Fundamenteel Onderzoek der Materie (FOM), Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands (NL)

According to a general nonperturbative theory that describes atomic behavior in intense, high-frequency radiation fields, the atom becomes stable against decay by multiphoton ionization in the limit of high frequencies if the parameter {alpha}{sub 0}=(I/2){sup 1/2}{omega}{sup {minus}2} (a.u.) (with {ital I} the intensity and {omega} the frequency of the field) is kept constant, although otherwise unrestricted. We show that, under this condition, in the subsequent limit of strong fields ({alpha}{sub 0} large), the Schroedinger equation describing the structure of the hydrogen atom in a laser field of circular polarization is separable in toroidal coordinates. Explicit asymptotic expressions are given for its energy eigenvalues and its eigensolutions. They correspond to a rapid decrease of the ionization potential and a drastic increase of the size of the atom with {alpha}{sub 0}. For the binding energy of the ground state we find: {vert bar}{ital E}{sub 0}{vert bar} =(1/2{pi}{alpha}{sub 0}) (ln{alpha}{sub 0}+2.654284) (a.u.). A dramatic distortion of the shape of the atom is found, which in the strong field becomes a torus-shaped object. Furthermore, we introduce a classification of its states by strong-field quantum numbers. We show how the levels at low {alpha}{sub 0}, characterized by the weak-field quantum numbers introduced earlier, and the levels at high {alpha}{sub 0}, characterized by the strong-field quantum numbers, are correlated. We find that the energy spectrum in strong fields displays a multiplet structure. A comparison is made between our analytical results and those of a numerical calculation carried out earlier.

• OSTI ID: 5245404
• Journal Information: Physical Review (Section) A: General Physics; (USA), Vol. 40:10; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
STARK EFFECT
ATOMS
AUGMENTATION
IONIZATION POTENTIAL
LASER RADIATION
MULTI-PHOTON PROCESSES
SCHROEDINGER EQUATION
SPECTRAL SHIFT
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
EQUATIONS
NONMETALS
PARTIAL DIFFERENTIAL EQUATIONS
RADIATIONS
WAVE EQUATIONS
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory