103 research outputs found
Landau-Bogolubov Energy Spectrum of Superconductors
We demonstrate that a dispersion relation of elementary excitations in the
Fermi liquid as a superconductor is identical to the one in a quantum liquid
HeII. Hence, we show that the superconductivity is, in fact, the same as
superfluidity, but for charged particles
Magnetization Cooling of an Electron Gas
We propose an adiabatic magnetization process for cooling the Fermi electron
gas to ultra-low temperatures as an alternative to the known adiabatic
demagnetization mechanism. We show via a new adiabatic equation that at the
constant density the increase of the magnetic field leads to the temperature
decrease as .Comment: Submitted to Physical Review Letter
Elementary Excitations in Quantum Fermi Liquid
Landau's theory of Fermi liquids is generalized by incorporating the de
Broglie waves diffraction. A newly derived kinetic equation of the Fermi
particles is used to derive a general dispersion relation and the excitation of
zero sound is studied. A new mode is found due to the quantum correction. It is
shown that the zero sound can exist even in an ideal Fermi gas. We also
disclose a new branch of frequency spectrum due to the weak interaction.Comment: Submitted to Physical Review Letter
Relativistic Thermodynamics of Magnetized Fermi Electron Gas
To study the relativistic thermodynamic properties of a Fermi gas in a strong
magnetic field, we construct the relativistic thermodynamic potential by the
relativistic Fermi distribution function taking into account that the motion of
particles in a plane perpendicular to the magnetic field is quantized. With
this general potential at hand, we investigate all the thermodynamic quantities
as a function of densities, temperatures and the magnetic field. We obtain a
novel set of adiabatic equations. Having the expression of the pressure and
adiabatic state equations, we determine the sound velocity for several cases
revealing a new type of sound velocity. Finally, we disclose the magnetic
cooling in the quantized electron Fermi gas, which is based on an adiabatic
magnetization in contrast to the known adiabatic demagnetization.Comment: arXiv admin note: text overlap with arXiv:0911.0133, arXiv:1212.227
On Dust Charging Equation
A general derivation of the charging equation of a dust grain is presented,
and indicated where and when it can be used. A problem of linear fluctuations
of charges on the surface of the dust grain is discussed.Comment: Invited Talk National Symposium on Plasma Physics Jan 28, 2008
Islamaba
Excitation of Longitudinal Waves in a Degenerate Isotropic Quantum Plasma
A dispersion equation, which describes the interaction of low density
electron beam with a degenerate electron quantum plasma, is derived and
examined for some interesting cases. In addition to the instabilities similar
to those for classical plasma, due to the quantum effect a new type of
instability is found. Growth rates of these new modes, which are purely
quantum, are obtained. Furthermore, the excitation of Bogolyubov's type of
spectrum by a strong electric field is discussed.Comment: Submitted to Journal of Plasma Physics special issu
Weibel instability in relativistic asymmetric electron positron plasma
We consider a situation in when the interaction of relativistically intense
EM waves with an isotropic electron positron plasma takes place, i.e.,we
consider short pulse lasers with intensity up to 1021 W/cm2, in which the
photon density is of the order of 1030cm3 and the strength of electric field E
= 10^9 statvolt/cm. Such a situation is possible in astrophysical and
laboratory plasma which are subject to intense laser radiation, thus leading to
non thermal equilibrium field radiations. Such interaction of the super-strong
laser radiation with an isotropic pair plasma leads to the generation of low
frequency electromagnetic EM waves and in particular a quasistationary magnetic
field. When the relativistic circularly polarized transverse EM wave propagates
along z- axis, it creates a ponderomotive force, which affects the motion of
particles along the direction of its propagation. On the other hand, motion of
the particles across the direction of propagation is defined by the
ponderomotive potential. Moreover dispersion relation for the transverse EM
wave using a special distribution function, which has an anisotropic form, is
derived and is subsequently investigated for a number of special cases. In
general, it is shown that the growth rate of the EM wave strongly depends upon
its intensity
Nonlinear Dynamics of Incoherent Superstrong Radiation in a Plasma
We present a new concept of nonlinear dynamics of incoherent superstrong
radiation in plasmas. Recently we have disclosed a novel mechanism of the
establishment of equilibrium between a photon and a dense photon bunch through
the exchange of longitudinal photons (Tsintsadze 2004 Phys. Plasmas 11, 855).
Based on this mechanism of the "Compton" scattering type, we have generalized
Wigner-Moyal equation for the dense photon gas, including the collision
integral for the occupation number of photons. In the geometric optics
approximation the Wigner-Moyal type of equation reduces to the one particle
Vlasov-Boltzmann equation for the photon gas. From this equation, which gives a
microscopic description of the photon gas, we derive a set of fluid equations,
and consider numerically the formation of 3D shock waves.Comment: Topical Review Talk ICPP0
Electromagnetic Solitons in Degenerate Relativistic Electron-Positron Plasma
The existence of soliton-like electromagnetic (EM) distributions in a fully
degenerate electron-positron plasma is studied applying relativistic
hydrodynamic and Maxwell equations. For circularly polarized wave it is found
that the soliton solutions exist both in relativistic as well as
nonrelativistic degenerate plasmas. Plasma density in the region of soliton
pulse localization is reduced considerably. The possibility of plasma
cavitation is also shown.Comment: Accepted for publication in Physica Script
Modulation instability of lower hybrid waves leading to cusp solitons in electron-positron-ion Thomas Fermi plasma
Following the idea of three wave resonant interactions of lower hybrid waves
it is shown that quantum -modified lower hybrid (QLH) wave in electron positron
ion plasma with spatial dispersion can decay into another QLH wave ( where
electron and positrons are activated whereas ions remain in the background) and
another ultra low frequency QULH (where ions are mobile). Quantum effects like
Bohm potential, exchange correlation and Fermi pressure on the lower hybrid
wave significantly reshaped the dispersion properties of lower hybrid waves.
Later a set of nonlinear Zakharov equations have been derived to consider the
formation of QLH wave solitons with the nonlinear contribution coming from the
QLH waves. Further, modulational instability of the lower hybrid wave solitons
is investigated and consequently it's growth rates are examined for different
limiting cases. Since the growth rate associated with the three-wave resonant
interaction are generally smaller than the growth associated with the
modulational instability, therefore only latter have been investigated. Soliton
solutions from the set of coupled Zakharov and NLS equations in the
quasi-stationary regime have been studied. Ordinary solitons are attribute of
nonlinearity whereas a cusp soliton solution featured by nonlocal nonlinearity
have also studied. Such an approach to lower hybrid waves and cusp solitons
study in Fermi gas comprising electron positron and ions is new and important.
The general results obtained in this quantum plasma theory will have widespread
applicability, particularly for processes in high energy plasma-laser
interactions set for laboratory astrophysics and solid state plasmas.Comment: 16 page
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