Quantum Plasma Research Articles

Günter Kelbg, the Kelbg potential and its impact on quantum plasma theory

AbstractGünter Kelbg did remarkable early work in the field of quantum statistical physics, in particular for dense quantum plasmas. In 2022 we celebrated his 100th birthday. On this occasion, we give a brief overview of his main scientific achievements in the field of quantum plasmas, complemented by some biographical background of his research and teaching environment at Rostock University. Kelbg's main achievement is the derivation of a regularized quantum pair potential. We demonstrate that it is still of high relevance for molecular dynamics and quantum Monte Carlo simulations of dense plasmas.

Ion acoustic solitons collision in spin-polarized relativistic quantum plasma

The dynamics of electrostatic ion acoustic solitons collision in relativistic magnetized spin-polarized plasma is studied using a Magnetized Relativistic Quantum Hydrodynamics model. The plasmas components are relativistic degenerate electron with spin-up (n e↑) and spin-down (n e↓) concentrations, and relativistic inertial classical ions. In two-dimensional plasma geometry, a homogeneous external magnetic field is provided along the z-direction, i.e. . The extended Poincare Lighthill Kuo (PLK) approach is used to calculate the Kortewegde Vries equations for oppositely moving ion-acoustic solitons. Before and after collision, their trajectories and associated phase shifts are computed. Only negative polarity pulses of ion acoustic solitons are observed in our stated relativistic magnetized plasma. The spin density popularization ratio κ is shown to have a significant impact on the phase shifts of colliding solitons. It is found that when κ increases, one soliton's phase shift increases while the other soliton's phase shift decreases. The relativistic effects are also analyzed numerically and found that the phase shift of colliding ions acoustic solitons grows as the relativistic component rises from weakly to ultra-relativistic. It is observed that the phase shift of both solitons is to be dependent on their phase velocity with each other. Our research is noteworthy in that it focuses on, the astrophysical systems such as white dwarf, neutron star and pulsar.

Time‐dependent charged particle stopping in quantum plasmas: testing the G1–G2 scheme for quasi‐one‐dimensional systems

AbstractWarm dense matter—an exotic, highly compressed state on the border between solid and plasma phases is of high current interest, in particular for compact astrophysical objects, high‐pressure laboratory systems, and inertial confinement fusion. For many applications, the interaction of quantum plasmas with energetic particles is crucial. Moreover, often the system is driven far out of equilibrium. In that case, there is high interest in time‐dependent simulations to understand the physics, in particular, during thermalization. Recently a novel many‐particle technique, the G1–G2 scheme was presented with reference to the study by Schlünzen et al. (2020) which allows for first‐principle simulations of the time evolution of interacting quantum systems. Here we apply this scheme to a spatially uniform dense quantum plasma (jellium) and explore its performance. To this end, the G1–G2 scheme is transformed into momentum representation, and first results are presented for a quasi‐one‐dimensional model system.

Impacts of a general power law on soliton for a (2+1)-dimensional Zakharov–Kuznetsov equation in magnetized quantum plasmas

In this article, under investigation is a (2+1)-dimensional Zakharov–Kuznetsov equation with a general power law nonlinearity arising from magnetized quantum plasmas model. The analytical periodic wave, bright soliton and bright–dark soliton solutions are computed for the equation via the F-expansion method. Furthermore, the impacts of the general power law parameter on the soliton is examined in details. It is interesting that the general power law can be used to control the amplitude and propagation speed, which can determine partly the kinetic energy. Particularly, as the general power law parameter increases, the soliton’ energy will decrease.

The effect of collisions on the rayleigh-taylor instability in magnetized quantum plasma

Rayleigh-Taylor instability occurs at the interface between light and heavy fluids whenever the heavier fluid is accelerated by the light one. An important issue is the stability conditions of these systems. Various parameters such as density difference between two fluids, density inhomogeneity length, magnetic field, viscosity, collision can affect the stabilization or destabilization of the system. So far, some of these factors have been investigated in the fields of classical and quantum physics. This process has also been studied in both linear and nonlinear states. Here we consider a collisional magnetic inhomogeneous quantum plasma. For the inhomogeneity profile of density as an exponential function, we calculated the second ordinary equation for the disturbed velocity. Since the differential equation does not have an analytical solution, we have calculated the growth rate curve using numerical methods and obtained the disturbed velocity profile in the discontinuity. Then the effects of different parameters such as collision, magnetic field, quantum effects, and density difference of two fluids on the system stabilization are studied. The various branches of the instability growth rate curve and its relationship with the turbulent velocity profile in discontinuity are also discussed.

Density polarization effect of spin-up and spin-down electrons on magnetosonic solitons in a dense plasma with oblique magnetic field

Nonlinear wave propagation of fast and slow magnetosonic waves is investigated in a magnetized quantum plasma with spin polarization effects of degenerate electrons. The multi-fluid quantum magnetohydrodynamic model is considered and two separate fluid dynamic equations for degenerate electrons i.e. spin-up and spin-down states (Pauli paramagnetism) with their different Fermi pressures. The ions are assumed to be classical and external magnetic field lies in a plane. The magnetization energy and current density of electrons due to the spin-1/2 effects are included in the momentum equation of the degenerate electrons and Maxwell equations, respectively. A Korteweg-de-Vries (KdV) equation is derived for nonlinear magnetosonic waves in a dense magnetized plasma with the inclusion of electron spin effects and oblique external magnetic field. The electron inertial effect (which causes wave dispersion) of both spin-up and spin-down state electrons is also included in the model. It is found that electron spin polarization density has significant effects on the phase speed and soliton structures (i.e. its width and amplitude) of fast (hump) and slow (dip) magnetosonic waves in a dense magnetized plasma. The present theoretical study along with the obtained numerical results may have possible applications towards many realistic astrophysical scenarios.

Obliquely propagating electron Bernstein wave in arbitrary degenerate plasma

Abstract On employing the linearized Vlasov–Maxwell model, the dispersion relation of obliquely propagating Bernstein wave in thermal electron gas including quantum effect of arbitrary/partial degeneracy in the presence of non-relativistic arbitrary magnetic field limits is derived. In particular, the results are obtained in the propagation range k z > k x with k x ≠ 0 under high frequency (ω ≫ k.v) and weak propagation (Ω ≫ k.v or k → 0) limits. The propagation angle θ ′ $\left({\theta }^{\prime }\right)$ defines the obliqueness of wave such that for θ′ = 0° and 90° we obtain the perpendicular propagating pure Bernstein wave and parallel propagating Langmuir wave, respectively. The graphical analysis of newly reported results is made under the numerically evaluated values and the previously reported results are also retained. The possible applications of present results are found in partially/arbitrary dense astrophysical quantum plasma e.g., in brown dwarfs as well as they have wide ranging potential applications in modern technology e.g., in semi-conductors.

An appearance of classical matter from the self-organizing process of quantum systems

We present a quantum effect where matter follows the classical Hamilton-Jacobi equation, which emerges from quantum systems with Riemannian structures, as in standard quantum systems such as semiconductor heterostructures, quantum plasmas, and quantum dots. The proposed effect is derived from solving a standard elliptic partial differential equation of the radial part of the wave function, which is equivalent to a vanished quantum potential of the system. We then analyze such an effect and examine how the classical matter tends to be denser at the boundary region of the system when the quantum system is given in a finite region in space. While the proposed effect is derived from the hydrodynamical formulation of quantum mechanics, the results are free from any interpretation of quantum mechanics.

Investigation of Rayleigh–Taylor instability and internal waves in strongly coupled rotating magnetized quantum plasma

Investigation of Rayleigh–Taylor instability and internal waves in strongly coupled rotating magnetized quantum plasma

On the collective properties of quantum media

We discuss the hydrodynamic representation of a wide class of quantum media exhibiting similar elementary excitations and dispersion properties. The representation covers quantum systems characterized by any type of (long-range) self-interaction, associated with an arbitrary potential. It also accounts for possible nonlinearities, which may arise, e.g., due to short-range interactions (collisions) in the case of bosons, or from the Pauli exclusion principle for fermions. The approach equally applies to various physical scenarios, such as self-gravitating quantum media (e.g., dark matter), quantum plasmas, Bose–Einstein condensates, and non-condensed cold atomic clouds. We discuss the formal analogies that can be drawn between these different systems and how they can be used to realize laboratory experiments emulating gravitational phenomena, especially in the context of alternative theories of gravity. To substantiate our point, we elaborate more closely on the case of non-minimal matter-curvature coupling gravity theories.

Instability of magnetosonic waves in magnetized degenerate half-spin-polarized quantum plasma

Shock and solitary waves in plasmas are the main focus of many current studies of localized disturbances in both laboratory and astrophysical plasmas. Here, the linear and the nonlinear properties evolving in three dimensions quantum magnetized spin-1/2 plasma formed of spin up (↑) and spin down (↓), nonrelativistic degenerate inertialess electrons, and classical ions, are considered. The nonlinear propagation is governed by a quantum Zakharov–Kuznetsov–Burger (QZKB) and QZK equations which are derived by using the multiple scales perturbation technique. The shock and solitary wave structures are dependent on the spin polarization parameter, Bohm potential, Zeeman energy, and dissipative parameter. The first, and the second, orders instability growth rates are also derived by using the small-k perturbation expansion method. The previous parameters affect also the instability growth rates. There is a critical angle below which the first order becomes positive while the second order is negative, and over which the first order disappears and the second order becomes positive. Our present results may be useful in understanding the dynamics in the magnetic pulsars, and also in the magnetic white dwarfs and neutron stars systems where degenerate spin-up and spin-down electrons with dissipative effects can exist.

Construction of Solitary Wave Solutions to the (3 + 1)-Dimensional Nonlinear Extended and Modified Quantum Zakharov–Kuznetsov Equations Arising in Quantum Plasma Physics

Several types of solitary wave solutions of (3 + 1)-dimensional nonlinear extended and modified quantum Zakharov–Kuznetsov equations are established successfully via the implantation of three mathematical methods. The concerned models have many fruitful applications to describe the waves in quantum electron–positron–ion magnetoplasmas and weakly nonlinear ion-acoustic waves in plasma. The derived results via the MEAEM method, ESE method, and modified F-expansion have been retrieved and will be expedient in the future to illuminate the collaboration between lower nonlinear ion-acoustic waves. For the physical behavior of the models, some solutions are plotted graphically in 2D and 3D by imparting particular values to the parameters under the given condition at each solution. Hence explored solutions have profitable rewards in the field of mathematical physics.

The phase shift in the collision of solitary waves with different angles in 2D unmagnetized quantum plasma

The phase shift in the collision of solitary waves with different angles in 2D unmagnetized quantum plasma

Localization of a Gaussian laser beam in thermal quantum plasma with density ramp

Localization of a Gaussian laser beam in thermal quantum plasma with density ramp

The role of electron inertia on jeans instability of radiative quantum plasma with the impact of rotation and resistivity

With the use of the Quantum Magnetohydrodynamic (QMHD) model, we took into account the Jeans instability of rotating magnetized radiative quantum plasma under the impact of finite electron inertia and resistivity. The issue is set up and using the linearization method and normal mode technique, we can get the general dispersion relation, which is then described in terms of various modes of propagation. Within the prescribed boundaries, we also get the Jeans instability criteria. Plotting the curves between the system's growth rate and wave number for the investigation of the stability analysis of the system, which is then thoroughly explained.

Hydrogen-, Helium-, and Lithium-like Bound States in Classical and Quantum Plasmas

We study the effective interactions and the mass action constants for pair and triple associations in classical and quantum plasmas. Avoiding double counting, we derive new expressions for the mass action constants. The calculations resulted in values that were substantially smaller than the standard ones in relevant temperature ranges by up to 50 percent. On this basis, we determine the pressure of H, He and Li plasmas and the osmotic coefficient of electrolytes with higher charges such as, e.g., seawater. Classical and quantum Coulomb systems show strong similarities. The contributions in low orders with respect to the interaction e2 are suppressed by thermal and screening effects. The contributions of weakly bound states, near the continuum edge, to the mass action constants are reduced, replacing the exponential functions with cropped exponentials. The new mass action constants are consistent with well-known extended limiting cases of screening effects. We analyze classical examples including the salts CaCl2 and LaCl3, and a model of seawater including multiple associations. In the case of quantum systems, we follow the work of Planck–Brillouin–Larkin for H plasmas and study He and Li plasmas. The equation of state (EoS) for wide-density regions is obtained through the concatenation of the EoS for the low-density region of partial ionization with the EoS of degenerate plasmas, where all bound states are dissolved and Fermi, Hartree–Fock and Wigner contributions dominate.

Head on collision of ion–acoustic shock waves in weakly relativistic electron–positron–ion quantum plasma

In this work, we explore analytically the head on collision (HoC) of two ion acoustic shock wave in relativistic quantum plasma. Extended Poincaré Lighthill Kuo(PLK) method has been applied in this problem in a fruitful manner to study the HoC of waves which are rare in literature. Introducing the strained coordinates and expanding the field quantities into the parameter ϵ, a set of differential equations is obtained. Tangent Hyperbolic method is also used while investigating nonlinear interaction of this mode. These techniques are proven to be efficient enough to extract the essence of physics. Our major focus is to study the influence of plasma characteristics on shock wave phase shifts upon a head-on collision. The effects of the ratio of electrons to positron temperature, fractional concentration of positrons, quantum parameter, kinematic viscosity on the phase shift are studied. The findings suggest that shock interactions are distinct from those of solitons. It is also observed that the dispersion and dissipation of the colliding nonlinear structure have a combined role in the occurrence and modification of trajectory variations. The results of this work might be beneficial in studying the propagation and interaction of quantum ion–acoustic shock waves in dense astrophysical plasma systems (white dwarf star) and intense laser-solid density plasma investigations.

Magnetoacoustic Waves in a Dissipative Quantum Plasma With Spin-1/2 and Exchange-Correlation Effects

Using quantum magneto-hydrodynamic theory, the nonlinear propagation of magnetoacoustic waves have been investigated in a quantum magneto-plasma having dissipative ions fluid as well as quantum electrons and positrons, including exchange-correlation and electrons/positrons spin effects. The Korteweg-devris-Burger equation is derived employing the reductive perturbation method. It has been found that the quantum magneto-plasma system under consideration supports buth magnetoacoustic solitary and shock waves depending on the values of the plasma parameters. The effects of quantum plasma parameters (such as exchange-correlation coefficients, magnetic field strength, kinematic viscosity and the concentrations of electrons and positrons) on the magnetoacoustic shock waves (both monotonic shock waves and oscillatory shock waves) are examined. The profiles of both monotonic and oscillatory shock waves are found to be significantly affected by these parameters.The results of the current study may be useful to understand the properties of magnetoacoustic waves propagating in dense space plasma environments where the quantum mechanical effects of electrons and positrons are included.

Nonlinear Langmuir oscillations in an ultrarelativistic degenerate quantum electron-ion plasma

The investigation of the nonlinear Langmuir associations in an ultrarelativistic, fully degenerate quantum plasma, composed of stationary ions and warm electrons is considered. The quantum hydrodynamic model with the equation of state of electrons is used to derive a nonlinear differential equation that describes the chemical potential of electrons. Then, the Runge Kutta method is used to solve this equation numerically. Hence, the profiles of the chemical potential and electron number density are graphically presented. Numerical results show that the Bohm quantum force produces small scale quantum Langmuir oscillations along with the classical oscillations. These findings are helpful in understanding the features of nonlinear Langmuir waves in various astrophysical plasmas such as planetary interiors and compact objects.

Comparison study of the energy and instability of ion-acoustic solitary waves in magnetized electron–positron–ion quantum plasma

Notably, solitary waves that emerge from the nonlinear properties of plasmas are the main focus of many current studies of localized disturbances in both laboratory and astrophysical plasmas. By applying the reductive perturbation method, we derive the nonlinear homogeneous quantum Zakharov–Kuznetsov (QZK) equation in three-component collisionless quantum plasma consisting of electrons, positrons, and ions in the presence of an external static magnetic field. The solitary wave structures are dependent on the Bohm potential, magnetic field, obliqueness, species Fermi temperatures, and densities. The soliton’s electric field and energy are also derived and investigated, which were found to be reduced as the magnetic field increases. The instability growth rate is also derived by using the small-k perturbation expansion method. The previous parameters affect the instability growth rate as well. A comparison of the energy and instability growth rate behaviour against system parameters is carried out. Large energy and large instability growth rate occur at large values of positron density or lower values of ion density. At zero or small rotation angle, both decrease as the magnetic field increases. Our findings could help us understand the dynamics of magnetic white dwarfs, pulsar magnetospheres, semiconductor plasma, and high-intensity laser-solid matter interaction experiments where e-p-i plasma exists.