Quantum Diffraction Effects Research Articles

Electron-proton relaxation in hot-dense plasmas with a screened quantum statistical potential.

Modeling the nonequilibrium process between ions and electrons is of great importance in laboratory fusion ignition, laser-plasma interaction, and astrophysics. For hot and dense plasmas, theoretical descriptions of Coulomb collisions remain complicated due to quantum effect at short distances and screening effect at long distances. In this paper, we propose an analytical screened quantum statistical potential that takes into account both the short-range quantum diffraction effect and the long-range screening effect. By implementing the newly developed potential into the binary scattering framework, the electron-proton temperature relaxation in hot-dense hydrogen plasmas is investigated. In both the classical and quantum limits, analytical expressions for the Coulomb logarithm have been obtained, which are generally embedded in an asymptotic matching formula. Quantitative comparisons with molecular dynamics simulations and recent OMEGA experiments demonstrate that the present modeling is well suited to describe the temperature relaxation process between electrons and ions in hot-dense plasmas.

The combined effects of quantum and strong coupling on the nonlinear collective excitation in quantum dusty plasmas

The quantum hydrodynamic model for electrons and ions and the generalized hydrodynamic model for the strongly coupled dust particles are proposed in the strongly coupled quantum dusty plasma, where the combined quantum effects of quantum diffraction, quantum statistic pressure, as well as electron exchange and correlation effects are all considered in the quantum hydrodynamic model. The shear and bulk viscosity effects are included in the viscoelastic relaxation, which leads to the decay of the dust-ion-acoustic waves. The approximate time-dependent solitary solution is obtained by the momentum conservation law in the presence of viscosity.

Study of quantum electron diffraction for the LISA test-mass charging

The future Laser Interferometer Space Antenna (LISA) for gravitational wave detection in space and the precursor LISA Pathfinder missions rely on metal test masses (TMs) playing the role of free-falling geodesic-reference and interferometer end mirrors. Charge deposited on the TMs by high-energy particles of galactic and solar origin couples with stray electric fields thus perturbing the free-falling geodesic motion. In previous works it has been shown that sub-keV electrons play a relevant role for TM charging. In particular, electrons with energies below 100 eV show a wave-like behavior when impacting on the gold coatings of the TMs and electrode-housing (EH), the capacitive position sensor/actuator that surrounds the TMs. We aim at studying the effects of quantum diffraction of electrons on LISA Pathfinder and LISA TMs and EH gold lattice. We calculate the quantum diffraction probability of electrons with energies < 100 eV impinging on gold lattice from different directions by using the methods of quantum mechanics. The effects of electron quantum diffraction on LISA TM charging are reported here for the first time. This work is also of interest for the second-generation LISA-like space interferometers and for all space missions whose performance relies on free-falling metal test masses.

A Glimpse into Quantum Triplet Structures in Supercritical 3He.

A methodological study of triplet structures in quantum matter is presented. The focus is on helium-3 under supercritical conditions (4 < T/K < 9; 0.022 < ρN/Å-3 < 0.028), for which strong quantum diffraction effects dominate the behavior. Computational results for the triplet instantaneous structures are reported. Path integral Monte Carlo (PIMC) and several closures are utilized to obtain structure information in the real and the Fourier spaces. PIMC involves the fourth-order propagator and the SAPT2 pair interaction potential. The main triplet closures are: AV3, built as the average of the Kirkwood superposition and the Jackson-Feenberg convolution, and the Barrat-Hansen-Pastore variational approach. The results illustrate the main characteristics of the procedures employed by concentrating on the salient equilateral and isosceles features of the computed structures. Finally, the valuable interpretive role of closures in the triplet context is highlighted.

Quantum effects on the propagation of surface magnetoplasmon polaritons in a graphene-plasmonic structure

We investigate the properties of surface magnetoplasmon polaritons (SMPPs) in a graphene-plasmonic structure which is constructed as a graphene film sandwiched with two semi-infinite dielectrics under a perpendicular configuration. By solving Maxwell equations and quantum magneto-hydrodynamic equations with considering the quantum statistical and quantum diffraction effects, we deduce the dispersion relation of graphene SMPPs (GSMPPs) in detail. We show how the graphene electron density, the external magnetic field, and the dielectric constant, affect the features of the dispersion of GSMPPs in both classical and quantum cases. We find that the quantum effects (QEs) significantly alter the properties of GSMPPs, which are entirely different from those in a classical model. We find that the propagation speed of classical GSMPPs has small increases while the propagation speed of quantum GSMPPs has fast and sharp increases along with the increases in graphene electron density. We further find that the propagation speed decreases gradually by increasing the applied magnetic field in both classical and quantum GSMPPs. Moreover, we also find that the propagation speed of classical GSMPPs has fast decreases tending to zero at large wavenumber while the propagation speed of quantum GSMPPs has slow decreases tending to infinity with increasing the dielectric constant. Our findings elucidate that QEs play a crucial role in the properties of GSMPPs and their response to different parameters.

Quantum and Relativistic Effects on the KdV and Envelope Solitons in Ion-Plasma Waves

In this article, we investigate the linear and nonlinear behavior of ion-plasma waves in a two-component plasma containing ions and dust particles. We have studied the linear dispersion characteristics, nonlinear KdV solitons, and amplitude modulated electrostatic waves. Such ion-plasma wave modes in dust-ion plasma have been theoretically investigated by incorporating quantum diffraction and relativistic effects. Numerical analysis of the linear dispersion relation with variations of different parameters has been carried out. By employing the reductive perturbation technique the KdV equation describing the small amplitude solitary profile has been studied. Using the standard multiple scale perturbation method, a nonlinear Schrödinger (NLS) equation has been derived by including quantum and relativistic effects, which describes the nonlinear evolution of the ion-plasma waves in dust-ion plasma. The wave is found to become modulationally unstable beyond certain critical wavenumber. The critical wavenumber and the growth rate of modulational instability are shown to depend significantly on the relativistic motion of plasma particles and the quantum diffraction effect. The results presented in the article are expected to be helpful for understanding the propagation of finite amplitude ion-plasma waves in some laboratory and astrophysical plasma systems. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PACS</i> —52.59.Hq, 67.10.Jn, 52.20 −j, 52.25 −b, 52.30 −d, 52.35 Mw, 52.65 Vv

Resonant Interactions and Chaotic Excitation in Nonlinear Surface Waves in Dense Plasma

By employing a quantum hydrodynamic (QHD) model with appropriate boundary conditions, the nonlinear self-interaction of an electrostatic surface wave on otherwise homogeneous semibounded plasma with degeneracy effects is investigated. It has been found that a part of the second harmonic generated through self-interaction does not have a true surface wave feature but propagates obliquely away from the plasma–vacuum interface into the bulk of the plasma. Such a situation is obtained in laser–plasma interaction during surface etching, plasma processing, and so on. In this article, we study the harmonics generation mechanism, associated Lagrangian chaos, and harmonic conversation rate when an intense laser is incident on an unmagnetized plasma. The dense plasma displays quantum diffraction effects and other quantum statistical effects. We made use of perturbative analysis for the field quantities. The findings will help workers dealing with laser–plasma interaction so as to enhance the tendency of harmonic generation and energy localization.

Effects of exchange symmetry and quantum diffraction on amplitude-modulated electrostatic waves in quantum magnetoplasma

Effects of exchange symmetry and quantum diffraction on amplitude-modulated electrostatic waves in quantum magnetoplasma

Nonlinear excitations of magnetosonic solitary waves and their chaotic behavior in spin-polarized degenerate quantum magnetoplasma.

The quantum hydrodynamic model is used to study the nonlinear propagation of small amplitude magnetosonic solitons and their chaotic motions in quantum plasma with degenerate inertialess spin-up electrons, spin-down electrons, and classical inertial ions. Spin effects are considered via spin pressure and macroscopic spin magnetization current, whereas the exchange effects are considered via adiabatic local density approximation. By applying the reductive perturbation method, the Korteweg-de Vries type equation is derived for small amplitude magnetosonic solitary waves. We present the numerical predictions about the conservative system's total energy in spin-polarized and usual electron-ion plasma and observed low energy in spin-polarized plasma. We also observe numerically that the soliton characteristics are significantly affected by different plasma parameters such as soliton phase velocity increases by increasing quantum statistics, magnetization energy, exchange effects, and spin polarization density ratio. Moreover, it is independent of the quantum diffraction effects. We have analyzed the dynamic system numerically and found that the magnetosonic solitary wave amplitude and width are getting larger as the quantum statistics and spin magnetization energy increase, whereas their amplitude and width decrease with increasing spin concentration. The wave width increases for high values of quantum statistic and exchange effects, while their amplitude remains constant. Most importantly, in the presence of external periodic perturbations, the periodic solitonic behavior is transformed to quasiperiodic and chaotic oscillations. It is found that a weakly chaotic system is transformed to heavy chaos by a small variation in plasma parameters of the perturbed spin magnetosonic solitary waves. The work presented is related to studying collective phenomena related to magnetosonic solitary waves, vital in dense astrophysical environments such as pulsar magnetosphere and neutron stars.

Effects of Quantum Diffraction on the Propagation of E-A-W Solitary Structure in Fermi Plasma

Plasma state of matter can be studied in various types of situations. These studies are of great interest in Astrophysical objects like galaxies, accretion disk, neutron stars, etc, and laboratory plasma as well. Different objects demand different approaches to investigate the dynamics of the plasma. The relativistic effects in the motion of electrons in Quantum Plasma highly affect the characteristics of the solitary structure of the wave with two-temperature electrons. In this paper, considering the quantum hydrodynamic (QHD) model a dispersion relation is derived, and using standard perturbation technique, a mathematical model (i.e. nonlinear Schrodinger Equation) is studied for a wave with relativistic and quantum effects in it. We study the analysis for different values of diffraction coefficient, streaming velocity, and other plasma parameters as well. We analyze the stable rogue wave structure using NLSE and run simulations of those solitary profiles and rogue waves.

Weakly nonlinear interactions of collective oscillations in a correlated degenerate fluid

A generalized viscoelastic quantum hydrodynamic model is proposed for the dynamics of strongly correlated degenerate isothermal fluid. The quantum forces associated with the quantum diffraction effect along with the strong correlation effects are embedded in this transport equation through the viscoelastic relaxation of correlations. The collective dynamics of linear and nonlinear modes in such correlated degenerate fluid are also investigated. In the high-frequency oscillation (kinetic regime), the dynamics of the weakly nonlinear mode is found to be governed by a novel equation with a memory dependent non-local nonlinear term that describes the strong correlation effect. This novel equation is solved analytically and numerically. In the low-frequency oscillation (hydrodynamic regime), the weakly nonlinear mode is found to be governed by a Korteweg–de Vries Burgers' equation that exhibits dispersive shock wave. In both the dynamics, quantum diffraction introduces the dispersive effect.

Entanglement fidelity ratio for elastic collisions in non-ideal two-temperature dense plasma

The quantum diffraction and symmetry effects on the entanglement fidelity (EF) of different elastic electron–electron, ion–ion and electron–ion interactions are investigated in non-ideal dense plasmas. The partial wave analysis, an effective screened interaction potential including quantum mechanical diffraction and symmetry effects are employed to obtain the EF in a non-ideal dense plasma. We show that collision energy and temperatures of electron and ion have destructive effects on the entanglement in the system. In fact, by decreasing the temperature of plasma particles, the quantum effects become more prominent and the entanglement is elevated. Also, increase in the density of plasma leads to the enhancement of entanglement ratio. Additionally, some important characteristic parameters of the scattering such as differential, transport and total cross sections are calculated.

Effect of dynamic screening on the electron capture process in nonideal plasma

In this paper, the process of electron capture in nonideal plasma has been investigated. For this goal the Bohr-Lindhard method has been applied to obtain the electron capture cross section. All calculations have been done in the framework of the trajectories of incident electron near hydrogen ion (proton) obtained by the numerical simulation of the equations of motion. The effective interaction potential, which takes into account the static or dynamic screening effects at large distances and quantum diffraction effects at short distances, was used. The results of numerical calculations of the electron capture radius, differential and total cross section for different values of the density parameter and velocity are presented. It is shown that dynamic charge screening increases the capture cross sections in comparison with static screening.

Kinetic ionization and recombination coefficients in the dense semiclassical plasmas on the basis of the effective interaction potential

In this paper, the ionization and recombination coefficients of dense semiclassical hydrogen plasma on the basis of the effective interaction potential have been investigated. For this goal the Bohr – Lindhard method and method phase function have been applied to obtain the electron capture and ionization cross sections. The electron capture cross section has been calculated in the framework of the perturbation theory. The effective interaction potential, which takes into account the screening effects at large distances and quantum diffraction effects at short distances, was used. The results of the investigation show the behaviour of the calculated kinetic coefficients with a change in the plasma parameters: the ionization coefficient decreases with increasing density and (or) coupling parameter while the recombination coefficient increases.

Kinetic theory derivation of exchange-correlation in quantum plasma hydrodynamics

A quantum kinetic equation containing exchange-correlation described by an effective potential is derived, in a non-relativistic electrostatic quantum plasma. The velocity moments of the kinetic equation produce quantum fluid equations modified by the exchange-correlation potential. Closure of the hydrodynamic equations is achieved by expressing the pressure dyad in terms of the number density, using a quantum corrected local velocity displaced Wigner function equilibrium. The propagation of ion-acoustic waves in a quantum electron-ion plasma is analyzed, in the case of a completely degenerate electron gas. The fluid and kinetic approaches are compared and shown to agree in the long wavelength limit. A discussion on the equation of state and the role of the exchange-correlation and quantum diffraction effects is provided. Possible experimental parameters for the verification of the predictions are identified.

On the effect of fractional statistics on quantum ion acoustic waves

In this paper, I study the effect of a small deviation from the Fermi–Dirac statistics on the quantum ion acoustic waves. For this purpose, a quantum hydrodynamic model is developed based on the Polychronakos statistics, which allows for a smooth interpolation between the Fermi and Bose limits, passing through the case of classical particles. The model includes the effect of pressure as well as quantum diffraction effects through the Bohm potential. The equation of state for electrons obeying fractional statistics is obtained and the effect of fractional statistics on the kinetic energy and the coupling parameter is analyzed. Through the model, the effect of fractional statistics on the quantum ion acoustic waves is highlighted, exploring both linear and weakly nonlinear regimes. It is found that fractional statistics enhance the amplitude and diminish the width of the quantum ion acoustic waves. Furthermore, it is shown that a small deviation from the Fermi–Dirac statistics can modify the type structures, from bright to dark soliton. All known results of fully degenerate and non-degenerate cases are reproduced in the proper limits.

Stable plasmon excitations in quantum nanowires

Stable electrostatic plasmon excitations due to propagation of Gaussian electron pulses are studied in a cylindrical nanowire of radius “a” and length “L”. For this purpose, we consider conduction electrons that follow the quantum hydrodynamical model to account for quantum statistics, quantum diffraction, and exchange-correlation effects in the presence of classical static ions. The use of the well-known Fourier transform technique and the Trivelpiece-Gould configuration leads to the generalized dispersion for plasmons with finite mode quantization effects via the radial and azimuthal mode indices, as well with quantum settings. The excitations of plasmon wakefield appear when the electron beam propagates with a constant velocity along the axial direction of nanowires. The stability conditions are also analyzed for the existence of wakefield excitations by solving three important inequalities using typical parameters of gold nanowires. The results may prove useful for understanding the plasmon excitations in quantum nanowires, where electrons can be trapped and accelerated in the wakefield to emit radiation in the extreme-ultraviolet range.

Magnetosonic waves in a quantum plasma with arbitrary electron degeneracy.

Using a two-species quantum hydrodynamic model, we derive the quantum counterpart of magnetosonic waves, in a plasma with arbitrary degree of degeneracy and taking into account quantum diffraction effects due to the matter-wave character of the charge carriers. The weakly nonlinear aspects of the associated quantum magnetosonic wave are accessed by means of perturbation theory, with the derivation of a nonlinear evolution equation admitting solitons, namely, the Korteweg-deVries equation. The degeneracy and quantum diffraction effects on soliton propagation are determined. A qualitative change on weakly nonlinear magnetosonic waves appears when quantum diffraction matches certain conditions, producing shock solutions instead of solitons, within the approximation level. We also include explicit numeric estimates and a discussion on the coupling (nonideality) parameter for quantum plasmas with intermediate degeneracy degree.

Nonplanar ion acoustic waves in collisional quantum plasma

The dynamics of nonlinear ion acoustic waves (IAWs) is studied in homogeneous, unmagnetized, collisional quantum plasma consisting of electrons and ions in bounded nonplanar (cylindrical/spherical) geometries. By using the reductive perturbation method, the nonplanar Kakutani and Kawahara equation is derived to investigate the nonlinear quantum IAW profiles. The dissipation is introduced by taking into account the collision among the plasma constituents in presence of quantum diffraction effect. Numerically, the effects of various plasma parameters, such as, the collisional parameter (η), the quantum diffraction parameter H, have been examined on the propagation of nonplanar IAW structures in quantum plasma. It is shown that in nonplanar geometry, plasma parameters play a vital role on the basic features of nonlinear structures (viz. amplitude, width, speed, and so on). It is also found that the properties of IAW structures in nonplanar geometry significantly differ from those in planar geometry.

Nonlinear quantum ion acoustic shock wave dynamics with exchange-correlation effects

The dynamics of linear and nonlinear electrostatic shock excitations is studied in homogeneous, unmagnetized, unbounded and dissipative quantum plasma consisting of electrons and ions. The dissipation in the system is taken into account by incorporating the ion kinematic viscosity. The system is modelled using the quantum hydrodynamic equations in which the electrons are significantly affected by the quantum forces, viz., the quantum statistical pressure, the quantum Bohm potential and electron exchange-correlations due to electron spin. In the weakly nonlinear limit, using reductive perturbation method deformed Korteweg-de Vries Burgers’s (KdVB) equation, which elegantly combines the effects of nonlinearity, dispersion and dissipation is derived. It is found that the present model predicts the existence of both nonlinear oscillatory and monotonic shock structures. The temporal evolution, stability and phase-space dynamics of nonlinear ion acoustic shocks are investigated numerically to elucidate the effects of quantum diffraction, electron exchange correlation and ion kinematic viscosity.