55,449 research outputs found
Self Interference of Single Electrodynamic Particle in Double Slit
It is by the long established fact in experiment and theory that
electromagnetic waves, here as one component of an IED particle, passing a
double slit will undergo self inference each, producing at a detector plane
fringed intensities. The wave generating point charge of a zero rest mass, as
the other component of the particle, is maintained a constant energy and speed
by a repeated radiation reabsorption/reemission scheme, and in turn steered in
direction in its linear motion by the reflected radiation field, and will
thereby travel to the detector along (one of) the optical path(s) of the waves
leading to a bright interference fringe. We elucidate the process formally
based on first principles solutions for the IED particle and known principles
for wave-matter interaction.Comment: Presentation at The 6th Int. Symp. Quantum Theory and Symmetries,
Univ. Kent, 2009
Transition behavior of k-surface from hyperbola to ellipse
The transition behavior of the k-surface of a lossy anisotropic indefinite slab is investigated. It is found that, if the material loss is taken into account, the k-surface does not show a sudden change from hyperbola to the ellipse when one principle element of the permittivity tensor changes from negative to positive. In fact, after introducing a small material loss, the shape of the k-surface can be a combination of a hyperbola and an ellipse, and a selective high directional transmission can be obtained in such a slab
From Galaxy-Galaxy Lensing to Cosmological Parameters
Galaxy-galaxy lensing measures the mean excess surface density DS(r) around a
sample of lensing galaxies. We develop a method for combining DS(r) with the
galaxy correlation function xi_gg(r) to constrain Omega_m and sigma_8, going
beyond the linear bias model to reach the level of accuracy demanded by current
and future measurements. We adopt the halo occupation distribution (HOD)
framework, and we test its applicability to this problem by examining the
effects of replacing satellite galaxies in the halos of an SPH simulation with
randomly selected dark matter particles from the same halos. The difference
between dark matter and satellite galaxy radial profiles has a ~10% effect on
DS(r) at r<1 Mpc/h. However, if radial profiles are matched, the remaining
impact of individual subhalos around satellite galaxies and environmental
dependence of the HOD at fixed halo mass is <5% in DS(r) for 0.1<r<15 Mpc/h. We
develop an analytic approximation for DS(r) that incorporates halo exclusion
and scale-dependent halo bias, and we demonstrate its accuracy with tests
against a suite of populated N-body simulations. We use the analytic model to
investigate the dependence of DS(r) and the galaxy-matter correlation function
xi_gm(r) on Omega_m and sigma_8, once HOD parameters for a given cosmological
model are pinned down by matching xi_gg(r). The linear bias prediction is
accurate for r>2 Mpc/h, but it fails at the 30-50% level on smaller scales. The
scaling of DS(r) ~ Omega_m^a(r) sigma_8^b(r) approaches the linear bias
expectation a=b=1 at r>10 Mpc/h, but a(r) and b(r) vary from 0.8 to 1.6 at
smaller r. We calculate a fiducial DS(r) and scaling indices a(r) and b(r) for
two SDSS galaxy samples; galaxy-galaxy lensing measurements for these samples
can be combined with our predictions to constrain Omega_m and sigma_8.Comment: 18 pages, 10 figures, accepted for publication in The Astrophysical
Journa
Fermi-liquid ground state in n-type copper-oxide superconductor Pr0.91Ce0.09LaCuO4-y
We report nuclear magnetic resonance studies on the low-doped n-type
copper-oxide Pr_{0.91}LaCe_{0.09}CuO_{4-y} (T_c=24 K) in the superconducting
state and in the normal state uncovered by the application of a strong magnetic
field. We find that when the superconductivity is removed, the underlying
ground state is the Fermi liquid state. This result is at variance with that
inferred from previous thermal conductivity measurement and contrast with that
in p-type copper-oxides with a similar doping level where high-T_c
superconductivity sets in within the pseudogap phase. The data in the
superconducting state are consistent with the line-nodes gap model.Comment: version to appear in Phys. Rev. Let
Optical study of phase transitions in single-crystalline RuP
RuP single crystals of MnP-type orthorhombic structure were synthesized by
the Sn flux method. Temperature-dependent x-ray diffraction measurements reveal
that the compound experiences two structural phase transitions, which are
further confirmed by enormous anomalies shown in temperature-dependent
resistivity and magnetic susceptibility. Particularly, the resistivity drops
monotonically upon temperature cooling below the second transition, indicating
that the material shows metallic behavior, in sharp contrast with the
insulating ground state of polycrystalline samples. Optical conductivity
measurements were also performed in order to unravel the mechanism of these two
transitions. The measurement revealed a sudden reconstruction of band structure
over a broad energy scale and a significant removal of conducting carriers
below the first phase transition, while a charge-density-wave-like energy gap
opens below the second phase transition.Comment: 5 pages, 6 figure
First excited state calculation using different phonon bases for the two-site Holstein model
The single-electron energy and static charge-lattice deformation correlations
have been calculated for the first excited state of a two-site Holstein model
within perturbative expansions using different standard phonon bases obtained
through Lang-Firsov (LF) transformation, LF with squeezed phonon states,
modified LF, modified LF transformation with squeezed phonon states, and also
within weak-coupling perturbation approach. Comparisons of the convergence of
the perturbative expansions for different phonon bases reveal that modified LF
approach works much better than other approaches for major range of the
coupling strength.Comment: 11 pages (REVTEX), 4 postscript figure
High Kinetic Inductance Superconducting Nanowire Resonators for Circuit QED in a Magnetic Field
We present superconducting microwave-frequency resonators based on NbTiN
nanowires. The small cross section of the nanowires minimizes vortex
generation, making the resonators resilient to magnetic fields. Measured
intrinsic quality factors exceed in a T in-plane magnetic
field, and in a mT perpendicular magnetic field. Due to
their high characteristic impedance, these resonators are expected to develop
zero-point voltage fluctuations one order of magnitude larger than in standard
coplanar waveguide resonators. These properties make the nanowire resonators
well suited for circuit QED experiments needing strong coupling to quantum
systems with small electric dipole moments and requiring a magnetic field, such
as electrons in single and double quantum dots
The Nonlinear Permittivity Including Non-Abelian Self-interaction of Plasmons in Quark-Gluon Plasma
By decomposing the distribution functions and color field to regular and
fluctuation parts, the solution of the semi-classical kinetic equations of
quark-gluon plasma is analyzed. Through expanding the kinetic equations of the
fluctuation parts to third order, the nonlinear permittivity including the
self-interaction of gauge field is obtained and a rough numerical estimate is
given out for the important \vk =0 modes of the pure gluon plasma.Comment: 7 pages, shortened version accepted by Chin.Phys.Let
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