Search results for "Number"

Superheavy element flerovium (element 114) is a volatile metal.

2014

The electron shell structure of superheavy elements, i.e., elements with atomic number Z ≥ 104, is influenced by strong relativistic effects caused by the high Z. Early atomic calculations on element 112 (copernicium, Cn) and element 114 (flerovium, Fl) having closed and quasi-closed electron shell configurations of 6d(10)7s(2) and 6d(10)7s(2)7p1/2(2), respectively, predicted them to be noble-gas-like due to very strong relativistic effects on the 7s and 7p1/2 valence orbitals. Recent fully relativistic calculations studying Cn and Fl in different environments suggest them to be less reactive compared to their lighter homologues in the groups, but still exhibiting a metallic character. Expe…

Effects of the Surface and Finite Temperature on the Electronic Structure of Metal Clusters

1996

The most fascinating feature of simple metal clusters is the existence of the electronic shell structure. This was observed first in alkali[1] and noble metals[2] and later also in some other nontransition metals[3,4,5]. The shell structure is a consequence of nearly free valence electrons confined to a finite volume. A spherical potential will always lead to a shell structure, the origin of which is the orbital angular momentum l and the large degeneracy (2l+1) associated with it. However, this primitive shell structure is strengthened by ’accidental’ degeneracies between states having different principal quantum numbers. Thus the shell structure of a hydrogen atom is different from that o…

A new approach to interacting fields

1974

A model for a description of interaction, which involves particle creation, can be given as follows: (1) A smooth finite-dimensional manifoldM constitutes the configuration space of some interacting system. (2) The concept of an interacting field is formulated in terms of two-component objects which consist of a physical and a topological field component which are ‘derived’ fromM. (3) Interaction is described in terms of the topological linking number of the topological field components and in terms of the intrinsic field equations.

Resonant Raman scattering in quantum wells in high magnetic fields: Deformation-potential interaction.

1992

A theoretical study of one-phonon resonant Raman scattering in a quantum well (QW) in high magnetic fields has been performed. The Raman profiles are calculated as a function of magnetic field, quantum-well thickness, and laser frequency. The basic theory is first developed assuming parabolic masses in the plane perpendicular to the growth direction of the QW. Selection rules for deformation-potential-allowed scattering are given and a compact analytical expression for the Raman-scattering efficiency is obtained for infinite barriers. The double-resonance conditions are derived as a function of the magnetic field or well thickness. In a second part of the work, the heavy-hole\char21{}light-…

Particles with Spin 1/2 and the Dirac Equation

2013

In order to identify the spin of a massive particle one must go to its rest system, perform rotations of the frame of reference, and study the transformation behaviour of one-particle states. This prescription was one of the essential results of Chap. 6. Furthermore, the spin \(1/2\) (electrons, protons, other fermions) is described by the fundamental representation of the group \(SU(2)\). The eigenstates of the observables \(\mathbf{{s}}^2\) and \(s_3\) transform by the \(D\)-matrix \(\mathbf{D }^{(1/2)}(\mathbf R )\) which is a two-valued function on \(\mathbb{R }^3\).

How Universal is the Scaling Theory of Localization?

1991

The numerical implementation of the one-parameter scaling theory of localization is reviewed for the Anderson model of disordered solids. A finite-size scaling procedure is used to derive the 3D localization length and d.c.-conductivity from the raw data computed for quasi-1D systems by the strip-and-bar method. While a common scaling function can be unambiguously obtained for different distributions of the diagonal disorder in the Anderson model, discrepancies appear between the box and the Gaussian distribution with regard to the derived critical exponents. To discuss these effects, new results are presented for a triangular distribution, and a new method for the computation of the critic…

Kinetics of growth process controlled by convective fluctuations

2001

A model of the spherical (compact) growth process controlled by a fluctuating local convective velocity field of the fluid particles is introduced. It is assumed that the particle velocity fluctuations are purely noisy, Gaussian, of zero mean, and of various correlations: Dirac delta, exponential, and algebraic (power law). It is shown that for a large class of the velocity fluctuations, the long-time asymptotics of the growth kinetics is universal (i.e., it does not depend on the details of the statistics of fluctuations) and displays the power-law time dependence with the classical exponent $1/2$ resembling the diffusion limited growth. For very slow decay of algebraic correlations of flu…

Corrigendum to “Transition from ideal to viscous Mach cones in a kinetic transport approach” [Phys. Lett. B 710 (4–5) (2012) 641]

2014

Photoionization of Polarized Atoms Applications to Free Atoms and Ferromagnets

1996

Discussion of connections between different phenomena observed in seemingly different situations usually helps to better understanding of the physics of underlying processes. Some time ago Farago1 discussed analogies and contrasts between light polarization and electron spin polarization. He showed that though in both cases the same Stokes vector formalism2 can be applied, the analogies between them have rather limited validity. We will discuss here the applicability of equations derived for the description of photoionization of free polarized atoms3,4 to photoemission from ferromagnets5,6. We show that qualitative features of photoemission from core levels of ferromagnets are correctly rep…

Ionization energy ofLi6,7determined by triple-resonance laser spectroscopy

2007

Rydberg level energies for $^{7}\mathrm{Li}$ were measured using triple-resonance laser excitation, followed by drifted field ionization. In addition to the principal $n\phantom{\rule{0.2em}{0ex}}^{2}P$ series, weak Stark mixing from residual electric fields allowed observation of $n\phantom{\rule{0.2em}{0ex}}^{2}S$ and hydrogenic Stark manifold series at higher $n$. Limit analyses for the series yield the spectroscopic ionization energy ${E}_{I}(^{7}\mathrm{Li})=43\phantom{\rule{0.2em}{0ex}}487.159\phantom{\rule{0.2em}{0ex}}40(18)\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. The $^{6,7}\mathrm{Li}$ isotope shift (IS) was measured in selected $n\phantom{\rule{0.2em}{0ex}}^{2}…