37 research outputs found
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.
Matter in Strong Magnetic Fields
The properties of matter are significantly modified by strong magnetic
fields, Gauss (), as are typically
found on the surfaces of neutron stars. In such strong magnetic fields, the
Coulomb force on an electron acts as a small perturbation compared to the
magnetic force. The strong field condition can also be mimicked in laboratory
semiconductors. Because of the strong magnetic confinement of electrons
perpendicular to the field, atoms attain a much greater binding energy compared
to the zero-field case, and various other bound states become possible,
including molecular chains and three-dimensional condensed matter. This article
reviews the electronic structure of atoms, molecules and bulk matter, as well
as the thermodynamic properties of dense plasma, in strong magnetic fields,
. The focus is on the basic physical pictures and
approximate scaling relations, although various theoretical approaches and
numerical results are also discussed. For the neutron star surface composed of
light elements such as hydrogen or helium, the outermost layer constitutes a
nondegenerate, partially ionized Coulomb plasma if , and may be in
the form of a condensed liquid if the magnetic field is stronger (and
temperature K). For the iron surface, the outermost layer of the
neutron star can be in a gaseous or a condensed phase depending on the cohesive
property of the iron condensate.Comment: 45 pages with 9 figures. Many small additions/changes. Accepted for
publication in Rev. Mod. Phy
The harmonic oscillator in prolate spheroidal coordinates. I. Coulomb interaction of an oscillator proton with an exterior charge
The three dimensional harmonie oscillator has been quantized in prolate spheroidal coordinates using the properties of the constants of the motion. The coulomb interaction of an oscillator proton with an exterior charge has been investigated by means of both a first order perturbation calculation and the variational method. The same problem modified by the presence of a spin-orbit interaction has been emphasized. Comparison with other works related to the subject has been made.Demeur Marcel, Reidemeister G. The harmonic oscillator in prolate spheroidal coordinates. I. Coulomb interaction of an oscillator proton with an exterior charge. In: Bulletin de la Classe des sciences, tome 56, 1970. pp. 190-213
Description des états quasi moléculaires par un modèle à particules indépendantes
Le spectre d’énergie d’une particule plongée dans le potentiel :
[math]
où [math]
a été calculé en fonction du paramètre de déformation z0. Les valeurs extrêmes de ce paramètre correspondent d’une part à un noyau sphérique et d’autre part à deux noyaux sphériques identiques, le nombre de nucléons étant resté le même.
Ce spectre d’énergie est utilisé pour construire un modèle à particules indépendantes décrivant des noyaux déformés « en haltères ».
Un des résultats obtenus est la mise en évidence d’une orbitale liante [math] favorable à la formation d’un état [math] dans Be9 et à la formation d’états quasi-moléculaires du type B10-B10, B11-B11 et C12-C12