64 research outputs found
Real-time quantum field theory at finite temperature in an inhomogeneous media
The method of the real time perturbative calculations of nonequilibrium
averages is generalised to the case of varying chemical potential. Calculations
are performed in the frame of Zubarev's nonequilibrium density matrix approach.
In this approach perturbations of temperature and other thermodynamical
parameters are taken into account explicitly including nonlinear terms. It
differs from the Schwinger-Keldysh approach through the choice of more general
initial conditions for the density matrix.Comment: 10 LaTeX pages, 1 LaTeX figure included in main pape
Observation of new quantum interference effect in solids
In order to achieve quantum interference of free electrons inside a solid, we
have modified the geometry of the solid so that de Broglie waves interfere
destructively inside the solid. Quantum interference of de Broglie waves leads
to a reduction in the density of possible quantum states of electrons inside
the solid and increases the Fermi energy level. This effect was studied
theoretically within the limit of the quantum theory of free electrons inside
the metal. It has been shown that if a metal surface is modified with patterned
indents, the Fermi energy level will increase and consequently the electron
work function will decrease. This effect was studied experimentally in both Au
and SiO2 thin films of special geometry and structure. Work function reductions
of 0.5 eV in Au films and 0.2 eV in SiO2 films were observed. Comparative
measurements of work function were made using the Kelvin Probe method based on
compensation of internal contact potential difference. Electron emission from
the same thin films was studied by two independent research groups using
Photoelectron Emission Microscopy (PEEM).Comment: 11 pages, 5 figure
Non-equilibrium symmetry restoration beyond one loop
We calculate the strength of symmetry restoration effects in highly
non-equilibrium states which can arise, for example, during preheating after
inflation. We show that in certain parameter range the one-loop results are
unstable, requiring summation of multiloop diagrams. We solve this problem for
the model in the large -limit and show that the symmetry restoration
may be less effective than what predicted by the one-loop estimate.Comment: Latex, 12 pages, 2 postscript figure
C-V characterization and electric parameters of ZrO2 received by UV stimulated plasma anodizing
Low temperature technologies creating metals oxides are a promising solution for formation integral circuit elements. In this report the electric properties of zirconia (ZrO2) received by low temperature (~400oC) UV stimulated plasma anodizing have been investigated. Zirconia is a potential high-k dielectric material with potential applications as a gate insulator in transistors. This dielectric distinguished by good electric parameters. For this purpose, we used C-V characterization technique and calculate dielectric constant, flatband voltage, threshold voltage, bulk potential, work function, oxide effective charge, charge concentration. The C-V measurement was carried out on Keithley Instrument Semiconductor Parameter Analyzer 4200, oxide thickness was measured by reflectometer – MprobeVis System
Problems of Perturbation Series in Non-Equilibrium Quantum Field Theories
In the standard framework of non-equilibrium quantum field theories, the
pinch singularities associated to multiple products of -functions do
not cancel in a perturbative expansion unless the particle distributions are
those for a system in thermal and chemical equilibrium.Comment: 10 pages, 2 figures, Cern preprint CERN-TH.7271/9
Minimal Mixing of Quarks and Leptons in the SU(3) Theory of Flavour
We argue that flavour mixing, both in the quark and lepton sector, follows
the minimal mixing pattern, according to which the whole of this mixing is
basically determined by the physical mass generation for the first family of
fermions. So, in the chiral symmetry limit when the masses of the lightest (
and ) quarks vanish, all the quark mixing angles vanish. This minimal
pattern is shown to fit extremely well the already established CKM matrix
elements and to give fairly distinctive predictions for the as yet poorly known
ones. Remarkably, together with generically small quark mixing, it also leads
to large neutrino mixing, provided that neutrino masses appear through the
ordinary ``see-saw'' mechanism. It is natural to think that this minimal
flavour mixing pattern presupposes some underlying family symmetry, treating
families of quarks and leptons in a special way. Indeed, we have found a local
chiral family symmetry model which leads, through its dominant
symmetry breaking vacuum configuration, to a natural realization of the
proposed minimal mechanism. It can also naturally generate the quark and lepton
mass hierarchies. Furthermore spontaneous CP violation is possible, leading to
a maximal CP violating phase , in the framework of the
MSSM extended by a high-scale chiral family symmetry.Comment: 52 pages, LaTex, no figures; some typos corrected; journal versio
EUPRERA Report Vol. 1, No. 1 Women in Public Relations – A Literature Review (1982-2019)
info:eu-repo/semantics/publishedVersio
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