531 research outputs found
Physical Kinetics of Ferroelectric Hysteresis
The physical kinetics of single domain ferroelectric materials are studied
using Landau-Khalatnikov equation. The hysteretic curves are obtained
numerically. The effective coercive electric field theoretically varies with
the driving amplitude and frequency. The effects of thermal noise are explored
using the Fokker-Planck kinetic equation. The ferroelectric switching times are
discussed and Quantum effects are briefly explored.Comment: ReVTeX with three *eps figures. Six page
Landau-Khalatnikov Circuit model for Ferroelectric Hysteresis
We present the circuit equivalent of the Landau-Khalatnikov dynamical
ferroelectric model. The differential equation for hysteretic behavior is
subject to numerical computer simulations. The size and shape of the simulated
hysteretic loops depends strongly on the frequency and the amplitude of the
driving electric field. This dependence makes the experimental extraction of
the coercive electric field difficult. The bifurcation of the driven
Landau-Khalatnikov model is explained in detail.Comment: ReVTeX4 format, 6 pages, 6 figures *.ep
Gravitational Wave Detection with Michelson Interferometers
Electromagnetic methods recently proposed for detecting gravitational waves
modify the Michelson phase shift analysis (historically employed for special
relativity). We suggest that a frequency modulation analysis is more suited to
general relativity. An incident photon in the presence of a very long
wavelength gravitational wave will have a finite probability of being returned
as a final photon with a frequency shift whose magnitude is equal to the
gravitational wave frequency. The effect is due to the non-linear coupling
between electromagnetic and gravitational waves. The frequency modulation is
derived directly from the Maxwell-Einstein equations.Comment: 4 pages, 3 *.eps figures, RevTeX 4 forma
Temperature of a Compressed Bubble with Application to Sonoluminescence
The rise in temperature from the adiabatic compression of a bubble is
computed in thermodynamic mean field (van der Waals) theory. It is shown that
the temperature rise is higher for the noble gas atoms than for more complex
gas molecules. The adiabatic temperature rise is shown to be sufficient for
producing sonoluminescence via the excited electronic states of the atoms.Comment: 7 pages, 3 figure
Biological Nuclear Transmutations as a Source of Biophotons
Soft multi-photon radiation from hard higher energy reaction sources can be
employed to describe three major well established properties of biophoton
radiation; Namely, (i) the mild radiation intensity decreases for higher
frequencies, (ii) the coherent state Poisson counting statistics, and (iii) the
time delayed luminescence with a hyperbolic time tail. Since the soft photon
frequencies span the visible to the ultraviolet frequency range, the hard
reaction sources have energies extending into the nuclear transmutation regime.Comment: 5 Pages and 1 figur
Radiation Induced Landau-Lifshitz-Gilbert Damping in Ferromagnets
The Landau-Lifshitz-Gilbert damping coefficient employed in the analysis of
spin wave ferromagnetic resonance is related to the electrical conductivity of
the sample. The changing magnetization (with time) radiates electromagnetic
fields. The electromagnetic energy is then absorbed by the sample and the
resulting heating effect describes magnetic dissipative damping. The
ferromagnetic resonance relaxation rate theoretically depends on the geometry
(shape and size) of the sample as well as temperature in agreement with
experiment.Comment: 3 pages ReVTeX 4 forma
Thermal Superradiance and the Clausius-Mossotti Lorentz-Lorenz Equations
Electric polarization phenomena in insulating systems have long been
described in mean field theory by the (static) Clausius-Mossotti or (dynamic)
Lorentz-Lorenz polarizabilities. It is here shown, in the strong coupling
regime, that a thermodynamic phase instability exists in these models. The
resulting thermodynamic phase diagram coincides with that obtained from
Dicke-Preparata model of thermal superradiance.Comment: 6 pages LaTeX and 1 figure *.ep
Thermodynamic QED Coherence in Condensed Matter: Microscopic Basis of Thermal Superradiance
Electromagnetic superradiant field coherence exists in a condensed matter
system if the electromagnetic field oscillators undergo a mean displacement.
Transitions into thermal states with ordered superradiant phases have been
shown to theoretically exist in Dicke-Preparata models. The theoretical
validity of these models for condensed matter has been called into question due
to non-relativistic diamagnetic terms in the electronic Hamiltonian. The
microscopic bases of Dicke-Preparata thermal superradiance for realistic
macroscopic systems are explored in this work. The impossibility of diaelectric
correlations in condensed matter systems (via the Landau-Lifshitz theorem)
provides a strong theoretical basis for understanding the physical reality of
condensed matter thermodynamic superradiant phases.Comment: 11 pages, no figures, LaTeX forma
The Clausius-Mossotti Phase Transition in Polar Liquids
The conventional Clausius-Mossotti polarization equation of state is known to
be unstable for polar liquids having molecules with high polarizability. Room
temperature water is an important example. The instability in the polarization
equation of state is of the typical loop form requiring an ``equal area''
construction for studying the stable ordered phase. The ordered phase of a
Clausius-Mossotti polar liquid then consists of domains each having a net
polarization. The polarization may vary in direction from domain to domain. The
ordered phases are quite similar to those previously discussed on the basis of
Dicke superradiance.Comment: ReVTeX format, 3 figure
Gravitational Waves and the Sagnac Effect
We consider light waves propagating clockwise and other light waves
propagating counterclockwise around a closed path in a plane (theoretically
with the help of stationary mirrors). The time difference between the two light
propagating path orientations constitutes the Sagnac effect. The general
relativistic expression for the Sagnac effect is discussed. It is shown that a
gravitational wave incident to the light beams at an arbitrary angle will not
induce a Sagnac effect so long as the wave length of the weak gravitational
wave is long on the length scale of the closed light beam paths. The
gravitational wave induced Sagnac effect is thereby null.Comment: LaTeX format 1 *.eps figur
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