26 research outputs found
One-Electron and Two-Electron Atoms in Strong Magnetic Fields and Implications for Magnetic White Dwarfs and Pulsars.
We present a variational calculation, using Slater-type trial wavefunctions of the energy spectrum and ionization energy of the hydrogen atom in strong magnetic fields ranging from 10^ Gauss (typical of magnetic white dwarf surfaces) to 10 12 Gauss (typical of pulsar surfaces). In addition, we have calculated bound-bound transition probabilities. Furthermore, a method is developed to generalize the energy level results to any one-electron atom. In particular, results for He 11 are presented. We also present an exact calculation of the quadratic Zeeman wavelength displacements of the Balmer lines from DA white dwarfs in view of which the estimate of the surface magnetic fields is higher than that obtained by previous, less accurate calculations. Finally, the variational calculation is extended to two-electron atoms in strong magnetic fields: we present the energy spectrum and ionization energy of He I and the e l e c t r o n affinity of If-
Energy levels of light atoms in strong magnetic fields
In this review article we provide an overview of the field of atomic
structure of light atoms in strong magnetic fields. There is a very rich
history of this field which dates back to the very birth of quantum mechanics.
At various points in the past significant discoveries in science and technology
have repeatedly served to rejuvenate interest in atomic structure in strong
fields, broadly speaking, resulting in three eras in the development of this
field; the historical, the classical and the modern eras. The motivations for
studying atomic structure have also changed significantly as time progressed.
The review presents a chronological summary of the major advances that occurred
during these eras and discusses new insights and impetus gained. The review is
concluded with a description of the latest findings and the future prospects
for one of the most remarkably cutting-edge fields of research in science
today.Comment: 37 pages, 16 figures, 1 tabl
Finite-Difference Calculations for Atoms and Diatomic Molecules in Strong Magnetic and Static Electric Fields
Fully numerical mesh solutions of 2D quantum equations of Schroedinger and
Hartree-Fock type allow us to work with wavefunctions which possess a very
flexible geometry. This flexibility is especially important for calculations of
atoms and molecules in strong external fields where neither the external field
nor the internal interactions can be considered as a perturbation. The
applications of the present approach include calculations of atoms and diatomic
molecules in strong static electric and magnetic fields. For the latter we have
carried out Hartree-Fock calculations for He, Li, C and several other atoms.
This yields in particular the first comprehensive investigation of the ground
state configurations of the Li and C atoms in the whole range of magnetic
fields (0<B<10000 a.u.) and a study of the ground state electronic
configurations of all the atoms with 1<Z<11 and their ions A^+ in the
high-field fully spin-polarised regime. The results in a case of a strong
electric field relate to single-electron systems including the correct solution
of the Schroedinger equation for the H_2^+ ion (energies and decay rates) and
the hydrogen atom in strong parallel electric and magnetic fields.Comment: 20 pages, 7 figure
Spectrum of Neutral Helium in Strong Magnetic Fields
We present extensive and accurate calculations for the excited state spectrum
of spin-polarized neutral helium in a range of magnetic field strengths up to
G. Of considerable interest to models of magnetic white dwarf stellar
atmospheres, we also present results for the dipole strengths of the low lying
transitions among these states. Our methods rely on a systematically saturated
basis set approach to solving the Hartree--Fock self-consistent field
equations, combined with an ``exact'' stochastic method to estimate the
residual basis set truncation error and electron correlation effects. We also
discuss the applicability of the adiabatic approximation to strongly magnetized
multi-electron atoms.Comment: 19 pages, 7 figures, 10 table
The ground state of the Lithium atom in strong magnetic fields
The ground and some excited states of the Li atom in external uniform
magnetic fields are calculated by means of our 2D mesh Hartree-Fock method for
field strengths ranging from zero up to 2.35 10^8 T. With increasing field
strength the ground state undergoes two transitions involving three different
electronic configurations: for weak fields the ground state configuration
arises from the field-free 1s^22s configuration, for intermediate fields from
the 1s^22p_{-1} configuration and in high fields the 1s2p_{-1}3d_{-2}
electronic configuration is responsible for the properties of the atom. The
transition field strengths are determined. Calculations on the ground state of
the Li+ ion allow us to describe the field-dependent ionization energy of the
Li atom. Some general arguments on the ground states of multi-electron atoms in
strong magnetic fields are provided.Comment: 11 pages, 6 figures, submitted to Physical Review
The ground state of the carbon atom in strong magnetic fields
The ground and a few excited states of the carbon atom in external uniform
magnetic fields are calculated by means of our 2D mesh Hartree-Fock method for
field strengths ranging from zero up to 2.35 10^9 T. With increasing field
strength the ground state undergoes six transitions involving seven different
electronic configurations which belong to three groups with different spin
projections S_z=-1,-2,-3. For weak fields the ground state configuration arises
from the field-free 1s^2 2s^2 2p_0 2p_{-1}, S_z=-1 configuration. With
increasing field strength the ground state involves the four S_z=-2
configurations 1s^22s2p_0 2p_{-1}2p_{+1}, 1s^22s2p_0 2p_{-1}3d_{-2}, 1s^22p_0
2p_{-1}3d_{-2}4f_{-3} and 1s^22p_{-1}3d_{-2}4f_{-3}5g_{-4}, followed by the two
fully spin polarized S_z=-3 configurations 1s2p_02p_{-1}3d_{-2}4f_{-3}5g_{-4}
and 1s2p_{-1}3d_{-2}4f_{-3}5g_{-4}6h_{-5}. The last configuration forms the
ground state of the carbon atom in the high field regime \gamma>18.664. The
above series of ground state configurations is extracted from the results of
numerical calculations for more than twenty electronic configurations selected
due to some general energetical arguments.Comment: 6 figures,acc. Phys.Rev.
Energy spectrum of He II in a strong magnetic field and bound-bound transition probabilities
The ground state energy of the He ii (singly ionized helium) atom is determined in magnetic fields up to 1012 G. The 13 lowest excited states and bound-bound transition probabilities are calculated in magnetic fields from 107 to 109 G. © 1973 D. Reidel Publishing Company