Dispersion properties of electron acoustic waves in degenerate and non‐degenerate quantum plasmas

Abstract

The longitudinal response functions are used to generalize the dispersion properties of electron acoustic waves (EAWs) in the presence of quantum recoil, for isotropic, non-relativistic, degenerate/non-degenerate plasmas. In order to study the EAWs, the constituents of non-degenerate (thermal) plasma are considered to be of two groups of electrons having different number density and temperature, namely the cold electrons and the hot electrons. Similarly in degenerate (Fermi) plasma the two population of electrons are considered to be the thinly populated and the thickly populated electrons. The sparsely populated electrons are termed as cold electrons while the densely populated ones are termed as hot electrons. The ions are stationary which form the neutralizing background. The absorption coefficients for Landau damping with the inclusion of the quantum recoil in both plasmas are calculated and discussed. The results are discussed in the context of laser-produced plasma. K E Y W O R D Sdegenerate and nondegenerate plasma, electron acoustic waves, Landau damping, quantum plasma, quantum recoil INTRODUCTIONQuantum plasma is referred to be degenerate, when its species like electrons, positrons, and holes are at high densities and low temperature, [1] where the inter-particle distance is smaller in comparison to de-Broglie wavelength. [2] On the length scales, of the order of a few Angstrom, quantum effects start to play a major role in the dynamics of the system. The quantum effects have vast applications in plasma physics such as in nano-structures devices, [3] semiconductors, [4] quantum diodes, [5] quantum dots, [6] ultrasmall electronics devices, [7] and ultracold plasmas. [8] The quantum effects also play an important role in both the laboratory plasmas, that is, laser-produced plasmas, [9] as well as in astrophysical plasmas like in the interiors of white dwarf and neutron stars. [10] By using the Lindhard dielectric function in a degenerate fermion plasma, the shielding of a moving point charge has been discussed. [11] The longitudinal response function for a thermal electron gas has been accounted by including the degeneracy, and the quantum recoil effects. [12] In the quantum fluid equations, the Bohm potential is the intrinsic quantum term, which is the consequence of quantum tunnelling effect of electrons. In plasma dynamics, the fluid approach is usually considered to be an approximation to a more general kinetic approach. Using the Vlasov equation Zhu et al, [13] investigated the Landau damping for electron plasma waves. They incorporated the quantum correction term, that is, Bohm potential as a quantum force.Recently the dispersion relation for ion acoustic waves (IAW) with the corresponding Landau damping were derived [14] for non-degenerate Maxwellian plasmas by using quantum treatment of kinetic theory, [15][16][17] (the generalized longitudinal response function) which we refer to a quantum plasma dynamics (QPD).

Singular solitons interaction of dust ion acoustic waves in the framework of Korteweg de Vries and Modified Korteweg‐de Vries equations with (r,q) distributed electrons

“…Within the basic parameter permissible range, it is noticed that for a certain value of the parameter set the nonlinear coefficient of an Equation (17), that is, A tends to zero. This means the nonlinear part of the derived very well-known KdV equation is going to be annihilated and, this breaks the solitary waves form.…”

“…Nonlinear features in theoretical physics [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] associated with fluid mechanics, solid-state physics, plasma physics, optical fibres, biophysics, chemical kinematics, chemical physics, and geochemistry are revealed through framing mathematical models, derive nonlinear evolution equations (NLEEs), and getting its solutions.…”

“…Experimental and theoretical investigations [6][7][8][9][10][11][12][13][14][15][16][17][19][20][21][22][23][24] acknowledge the generation of low and very-low-frequency acoustic modes which have possible applications in space as well as laboratory plasmas. To explain important and global nonlinear features embedded within this system, attention to acquiring knowledge, through investigations of NLEEs and their solutions, [6][7][8][9][10][11][12][13][14][15][16][17] is therefore likely to have a profound. Travelling wave solutions of such NLEEs draws noticeable attention as this type of solution is profoundly associated with solitons theory.…”

Variable dust charge generates a special type of nonlinear structures through modified Gardner equations

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Super electron acoustic propagations in critical plasma density

“…Fahad et al studied the dispersion features of EA waves in non-relativistic quantum recoil with isotropic non-degenerate system. The coefficients of absorption for Landau damping were discussed for laser-produced plasmas [22]. Also, Yahia et al investigated the head-on EA collisions in quasi-elastic case in magnetized nonthermal plasma.…”