Nonlinear separate spin evolution in degenerate electron-positron-ion plasmas

Iqbal, Z.; Andreev, Pavel A.

doi:10.1063/1.4954908

Cited by 43 publications

(33 citation statements)

References 41 publications

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“…This estimation of the imaginary part is found by the iteration method assuming that the imaginary term in equation (11) is small. Solution (14) is in agreement with applied approximation if system has high spin polarization 1 − η ≪ 1.…”

Section: Oblique Propagation Of the Seaws In The Long-wavelength Lsupporting

confidence: 75%

Kinetic description of the oblique propagating spin-electron acoustic waves in degenerate plasmas

Andreev

2018

Physics of Plasmas

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Oblique propagation of the spin-electron acoustic waves in degenerate magnetized plasmas is considered in terms of quantum kinetics with the separate spin evolution, where the spin-up electrons and the spin-down electrons are considered as two different species with different equilibrium distributions. It is considered in the electrostatic limit. Corresponding dispersion equation is derived. Analytical analysis of the dispersion equation is performed in the long-wavelength limit to find an approximate dispersion equation describing the spin-electron acoustic wave. The approximate dispersion equation is solved numerically. Real and imaginary parts of the spin-electron acoustic wave frequency are calculated for different values of the parameters describing the system. It is found that the increase of angle between direction of wave propagation and the external magnetic field reduces the real and imaginary parts of spin-electron acoustic wave frequency. The increase of the spin polarization decreases the real and imaginary parts of frequency either. The imaginary part of frequency has nonmonotonic dependence on the wave vector which shows a single maximum. The imaginary part of frequency is small in compare with the real part for all parameters in the area of applicability of the obtained dispersion equation.

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Section: Oblique Propagation Of the Seaws In The Long-wavelength Lsupporting

confidence: 75%

Kinetic description of the oblique propagating spin-electron acoustic waves in degenerate plasmas

Andreev

2018

Physics of Plasmas

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“…Here, the Bessel functions J n are functions of k x v F s sin θ/ | Ω e |, if a Bessel function has different argument this argument is shown explicitly as it is in the third line in equation (18), and J ′ n means derivative of J n on its argument k x v F s sin θ/ | Ω e |. Two spin dependent terms in equation (18) contain the following matrix…”

Section: Wave Propagation Perpendicular To the External Magneticmentioning

confidence: 99%

Kinetic analysis of spin current contribution to spectrum of electromagnetic waves in spin-1/2 plasma. II. Dispersion dependencies

Andreev

2017

Physics of Plasmas

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The dielectric permeability tensor for spin polarized plasmas derived in terms of the spin-1/2 quantum kinetic model in six-dimensional phase space in Part I of this work is applied for study of spectra of high-frequency transverse and transverse-longitudinal waves propagating perpendicular to the external magnetic field. Cyclotron waves are studied at consideration of waves with electric field directed parallel to the external magnetic field. It is found that the separate spin evolution modifies the spectrum of cyclotron waves. These modifications increase with the increase of the spin polarization and the number of the cyclotron resonance. Spin dynamics with no account of the anomalous magnetic moment gives a considerable modification of spectra either. The account of anomalous magnetic moment leads to a fine structure of each cyclotron resonance. So, each cyclotron resonance splits on three waves. Details of this spectrum and its changes with the change of spin polarization are studied for the first and second cyclotron waves. A cyclotron resonance existing at ω ≈ 0.001 | Ωe | due to the anomalous magnetic moment is also described, where | Ωe | is the cyclotron frequency. The ordinary waves does not have any considerable modification. The electrostatic and electromagnetic Berstein modes are studied during the analysis of waves propagating perpendicular to the external magnetic field with the electric field perturbation directed perpendicular to the external field. A modification of the oscillatory structure caused by the equilibrium spin polarization is found in both regimes. Similar modification is found for the extraordinary wave spectrum.

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“…The author examined the evolution of electrons and contribution of magnetic field in the Langmuir wave dispersion via the different occupation of spin-up and spin-down states. The existence of spin-electron-positron acoustic spin-electron acoustic, and positron acoustic solitons in degenerate electron-positron-ion (e − p − i) plasmas were demonstrated by Iqbal and Andreev [18]. The influence of the spin polarisation on the properties of three kinds of solitons was also analysed.…”

Section: Introductionmentioning

confidence: 98%

Ion-Acoustic Cnoidal Waves with the Density Effect of Spin-up and Spin-down Degenerate Electrons in a Dense Astrophysical Plasma

Kaur

Saini

2019

Zeitschrift Für Naturforschung A

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An investigation of nonlinear ion acoustic (IA) cnoidal waves in a magnetised quantum plasma is presented by using spin evolution quantum hydrodynamics model, in which inertial classical ions and degenerate inertialess electrons with both spin-up and spin-down states taken as separate species are considered. The Korteweg-de Vries equation is derived using the reductive perturbation method. Further, using the Sagdeev pseudopotential approach, the solution for IA cnoidal waves is derived with suitable boundary conditions. There is the formation of only positive potential cnoidal, and in the limiting case, positive solitary waves are observed. The effects of density polarisation and other plasma parameters on the characteristic features of cnoidal and solitary waves have been analysed numerically. It is seen that the spin density polarisation significantly affects the characteristics of cnoidal structures as we move from strongly spin-polarised (µ = 1) to a zero spin-polarisation case (µ = 0). The results obtained in the present investigation may be useful in comprehending various nonlinear excitations in dense astrophysical regions, such as white dwarfs, neutron stars, and so on.

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Nonlinear separate spin evolution in degenerate electron-positron-ion plasmas

Cited by 43 publications

References 41 publications

Kinetic description of the oblique propagating spin-electron acoustic waves in degenerate plasmas

Kinetic description of the oblique propagating spin-electron acoustic waves in degenerate plasmas

Kinetic analysis of spin current contribution to spectrum of electromagnetic waves in spin-1/2 plasma. II. Dispersion dependencies

Ion-Acoustic Cnoidal Waves with the Density Effect of Spin-up and Spin-down Degenerate Electrons in a Dense Astrophysical Plasma

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