Search results for "Homogeneous"
showing 10 items of 718 documents
Broken symmetries in the reconstruction of ν=1 quantum Hall edges
1999
Spin-polarized reconstruction of the v=1 quantum Hall edge is accompanied by a spatial modulation of the charge density along the edge. We find that this is also the case for finite quantum Hall droplets: current spin density functional calculations show that the so-called Chamon-Wen edge forms a ring of apparently localized electrons around the maximum density droplet (MDD). The boundaries of these different phases qualitatively agree with recent experiments. For very soft confinement, Chern-Simons Ginzburg-Landau theory indicates formation of a non-translational invariant edge with vortices (holes) trapped in the edge region.
Spin and rotational symmetries in unrestricted Hartree–Fock states of quantum dots
2007
Ground state energies are obtained using the unrestricted Hartree Fock method for up to four interacting electrons parabolically confined in a quantum dot subject to a magnetic field. Restoring spin and rotational symmetries we recover Hund first rule. With increasing magnetic field, crossovers between ground states with different quantum numbers are found for fixed electron number that are not reproduced by the unrestricted Hartree Fock approximation. These are consistent with the ones obtained with more refined techniques. We confirm the presence of a spin blockade due to a spin mismatch in the ground states of three and four electrons.
Jahn-Teller deformations of jellium slices
1997
Equilibrium geometries of quasi two-dimensional jellium systems are calculated in the local density approximation, closely following the “Ultimate Jellium Model” of [1]. The background charge is assumed to be fully deformable in a layer between two parallel planes, whereas the wave functions in the direction perpendicular to such a “jellium slice” are confined to their ground state. Like for jellium clusters in three dimensions [1], we find that for various system sizes, a trend towards a breaking of axial and inversion symmetries is observable.
Local nuclear energy density functional at next-to-next-to-next-to-leading order
2008
We construct nuclear energy density functionals in terms of derivatives of densities up to sixth, next-to-next-to-next-to-leading order (N3LO). A phenomenological functional built in this way conforms to the ideas of the density matrix expansion and is rooted in the expansions characteristic to effective theories. It builds on the standard functionals related to the contact and Skyrme forces, which constitute the zero-order (LO) and second-order (NLO) expansions, respectively. At N3LO, the full functional with density-independent coupling constants, and with the isospin degree of freedom taken into account, contains 376 terms, while the functionals restricted by the Galilean and gauge symme…
Yukawa Alignment in the Two-Higgs-Doublet Model
2009
5 páginas, 1 tabla.-- PACS numbers: 12.60.Fr, 11.30.Hv, 12.15.Mm, 14.80.Cp
top data system (TDS) software for spectrum simulation of asymmetric molecules
2005
Abstract The D 2 h TDS ( D 2 h Top Data System) program suite has been developed with the aim of studying any rovibrational band or polyad of X 2 Y 4 ( D 2 h ) asymmetric top molecules. It is based on the same principles as similar programs from our group already released for various molecular symmetries ( T d , O h , C 4 v , C 2 v ). We work in the O ( 3 ) ⊃ D 2 h chain and this choice has consequences on the method used to specify the input parameters of the programs for Hamiltonian and transition moment calculations. Two examples concerning the ν 12 and ν 2 bands of the C 2 H 4 molecule are presented. This suite consists of a series of FORTRAN programs called by a script. The whole packa…
The finite element method for fractional non-local thermal energy transfer in non-homogeneous rigid conductors
2015
Abstract In a non-local fractional-order model of thermal energy transport recently introduced by the authors, it is assumed that local and non-local contributions coexist at a given observation scale: while the first is described by the classical Fourier transport law, the second involves couples of adjacent and non-adjacent elementary volumes, and is taken as proportional to the product of the masses of the interacting volumes and their relative temperature, through a material-dependent, distance-decaying power-law function. As a result, a fractional-order heat conduction equation is derived. This paper presents a pertinent finite element method for the solution of the proposed fractional…
Quantum dots in magnetic fields: Unrestricted symmetries in the current spin-density functional formalism
1999
We apply the current spin-density functional formalism (CSDFT) of Vignale and Rasolt to two-dimensional quantum dots in magnetic fields. Avoiding any spatial symmetry restrictions of the solutions, we find that a broken rotational symmetry of the electronic charge density can occur in high magnetic fields.
Electroweak precision data and right-handed gauge bosons
1998
The implication of recent electroweak precision data for left-right symmetric models is examined. We establish a lower bound on the charged and neutral right-handed gauge bosons independent of the right-handed neutrino mass and of any restrictions or implied symmetries on the right KM matrix.
Zur Frage der Charakterisierung stationärer Bewegungen in der Hydrodynamik
1958
Helmholtz andKorteweg propose that the steady motion of a viscous fluid under constant extraneous forces having a single-valued potential dissipates—for any given region and assuming that inertia terms in the dynamic equations can be neglected—less energy than any other motion with the same values of velocity at the boundary.—A generalization of this proposition is here given, and an application discussed. The application deals with the motion of a simple macromolecule model in an inhomogeneous field of flow—a motion caused only by the influence ofStokes' friction.