Quantum Plasma Half-space Research Articles

Electrostatic Surface Waves in Magnetized Quantum Plasma Half-Space with Application of Metallic Gold

Electrostatic Surface Waves in Magnetized Quantum Plasma Half-Space with Application of Metallic Gold

Effects of spin polarization on the propagation of surface waves on a quantum plasma half-space

The study explores the wave propagation characteristics of surface plasma waves in a semi-bounded plasma, incorporating the influence of spin polarization arising from spin mismatch. The formulated plasma model integrates the density correlation effect via Bohm's potential force, Fermi pressure employing Fermi-Dirac statistics, and the exchange potential. These factors are considered in spin-polarized form and interconnected through the spin polarization index κ. We derive a dispersion relation for surface plasma waves, delineating the propagation features of the configured wave mode. Our findings indicate that an increase in spin polarization among electron populations results in a decrease in the phase velocity of surface plasma waves compared to the usual electron-ion quantum plasma. Moreover, an increase in the exchange potential contributes to a decrease in the phase speed. However, the ratio of plasmon to Fermi energy leads to an increase in the phase velocity of surface plasma waves in a spin-polarized quantum plasma. We provide a comparative analysis of our work with an earlier model based on the gold–air interface, revealing that our model facilitates the propagation of surface plasma waves with higher frequencies across the wave vector. This study highlights the significance of quantum effects for electrostatic surface plasma waves in dense metallic plasmas at room temperature, with implications for signal transmission in metallic waveguides observed in a recent study [Guo et al., “Excitation of graphene magneto-plasmons in terahertz range and giant Kerr rotation,” J. Appl. Phys. 125(1), 013102 (2019)] and some of the references therein.

Boundary graphene layer effect on surface plasmon oscillations in a quantum plasma half-space

The effect of graphene on unique features of surface plasmon-polariton excitations near the interface of vacuum and quantum plasma half-space is explored using a quantum hydrodynamic model including the Fermi electron temperature and the quantum Bohm potential together with the full set of Maxwell equations. It is found that graphene as a conductive layer significantly modifies the propagation properties of surface waves by making a change on the corresponding wave dispersion relation. It is shown that the presence of graphene layer on the interface of vacuum and plasma leads to a blue-shift in the surface Plasmon frequency. The results of present study must be contributed to the modern electronic investigations.

Propagation of surface waves in a spin 1/2 magnetized collisional quantum plasma half-space

The quantum magnetohydrodynamics model, including the correction terms of the Bohm potential, quantum pressure, collision and intrinsic spin of electrons, is employed to investigate the propagation of surface waves in a semi-bounded spin 1/2 magnetized collisional quantum plasma. The parametric equation method is used to derive the highly nonlinear dispersion relation. Furthermore, the exact dispersion relation is solved numerically. It is shown that the external magnetic field increases the group and phase velocities of the surface waves in both collisionless and collisional quantum plasma, while the spin contribution leads to a decrease in the phase velocity. In the collisional quantum plasma, the damping rate of the surface waves is increased by the external magnetic field and the spin of the electrons.

Multiple surface plasmons in an unbounded quantum plasma half-space

The propagation of surface plasmons on a quantum plasma half-space in the absence of any external confinement is investigated. By means of the Quantum Hydrodynamic Model in the electrostatic limit, it is found that the equilibrium density profile is a smooth continuous function which, in the linear regime, supports multiple non-normal surface modes. Defining a spectrum function and using a cutting condition, the dispersion relations of these modes and their relevance for realistic dynamics are computed. It is found that the multiple surface plasmons present a significant red-shift with respect to the case of fully bounded quantum plasmas.

Comment on “Surface electromagnetic wave equations in a warm magnetized quantum plasma” [Phys. Plasmas 21, 072114 (2014)

In a recent article [C. Li et al., Phys. Plasmas 21, 072114 (2014)], Li et al. studied the propagation of surface waves on a magnetized quantum plasma half-space in the Voigt configuration (in this case, the magnetic field is parallel to the surface but is perpendicular to the direction of propagation). Here, we present a fresh look at the problem and obtain a new form of dispersion relation of surface waves of the system. We find that our new dispersion relation does not agree with the result obtained by Li et al.

Electrostatic surface waves on a magnetized quantum plasma half-space

A theory of electrostatic surface waves on a quantum plasma half-space is developed with the inclusion of external magnetic field effects for the geometry in which the magnetic field is parallel to the surface and the direction of propagation is perpendicular to the magnetic field. A general analytical expression for dispersion relation of surface waves is obtained by solving Poisson and quantum magnetohydrodynamic equations with appropriate quantum boundary conditions.

Response to “Comment on ‘Surface waves on quantum plasma half-space with electron exchange-correlation effects’” [Phys. Plasmas 23, 034701 (2016)

The main differences between our work [H. Khalilpour, Phys. Plasmas 22, 122112 (2015)] and the work of Shahmansouri [Phys. Plasmas 22, 092106 (2015)] are summarized. Also, the validity of the pre-factor 1/9 in front of Bohm potential is discussed.

Comment on “Surface waves on quantum plasma half-space with electron exchange-correlation effects” [Phys. Plasmas 22, 122112 (2015)

More recently, Khalilpour in his paper [Phys. Plasmas 22, 122112 (2015)] has studied the dispersion relation for propagation of surface waves in a half-space quantum plasma using a hydrodynamic model including the electron exchange-correlation effect, which he calls the modified quantum hydrodynamic model. While this paper looks similar to the previously published one [M. Shahmansouri, Phys. Plasmas 22, 092106 (2015)] in structure, the only difference appears to be inclusion of the recently suggested kinetic factor of γ=1/9 for the quantum Bohm potential. In this comment, we would like to clarify the application of the mentioned factor in the standard quantum hydrodynamic model and stress out that the so-called modified quantum fluid model does not exist and the current extension of author is meaningless in the context of quantum hydrodynamics.

Surface waves on quantum plasma half-space with electron exchange-correlation effects

The propagation of surface waves on a quantum plasma half-space is investigated, taking into account the electron exchange-correlation effect. Using the modified quantum hydrodynamic model in conjunction with the Poisson equation, the dispersion relation of surface waves is obtained. It is found that due to the presence of electron exchange-correlation effect the wave frequency is shifted to lower frequencies. For different ranges of Brueckner parameter rs, the effect of electron exchange-correlation is investigated. It is indicated that for weak coupling region with rs < 0.1, the wave frequency remains unchanged and in this region the effect of electron exchange-correlation is negligible. For moderate coupling region, i.e., (0.1 < rs < 1), the influence of electron exchange-correlation is important and as rs increases, the electron exchange-correlation effect also increases.

The exchange-correlation effects on surface plasmon oscillations in semi-bounded quantum plasma

We studied the surface plasmon waves in a quantum plasma half-space by considering the effects of exchange and correlation for the electrons. We used a quantum hydrodynamic approach, including the full set of Maxwell equations and considering two new quantities (measuring the exchange and correlation effects) in addition to the Fermi electron temperature and the quantum Bohm potential, to derive the dispersion relation for the surface plasmon waves. It was found that the exchange-correlation effects significantly modified the behavior of surface plasmon waves. We showed that the frequency of surface plasmon wave was down-shifted by the exchange-correlation effects. On the other hand, the quantum effects (including of the exchange-correlation effects and the quantum Bohm potential) was seen to cause an increase in the phase speed of surface plasmon waves. Our results can help to understand the propagation properties of surface waves in intense laser produced solid density plasmas and metallic plasmas.

Quantum ion-acoustic wave oscillations on a quantum plasma half-space

We investigate the dispersion properties of surface quantum ion-acoustic wave oscillations on an electron–ion quantum plasma half-space, taking into account the quantum diffraction effects. We deduce the perturbed electron density by using the linearized quantum fluid model, while the ion density perturbation is obtained by the classical theory. We derive an analytical dispersion relation for the surface waves of the system with low-frequency, by applying the Poisson equation as well as the appropriate boundary conditions. We use the dimensionless parameter H, proportional to quantum tunneling effects and show the system support linear quantum ion-acoustic waves, where in the limit of small H, the classical ion-acoustic waves emerge.

Surface plasmon oscillations on a quantum plasma half-space

We investigate the propagation of surface electrostatic oscillations on a quantum plasma half-space, taking into account the quantum effects. We derive the quantum surface wave frequencies of the system, by means the quantum hydrodynamic theory in conjunction with the Poisson equation and applying the appropriate additional quantum boundary conditions. Numerical results show in the presence of the slow nonlocal variations, plasmon wave energies of the system are significantly modified and plasmonic oscillations with blue-shifted frequencies emerge.

Dust-Lower-Hybrid Surface Waves in Classical and Degenerate Plasmas

The dispersion relation for general dust low frequency electrostatic surface waves propagating on an interface between a magnetized dusty plasma region and a vacuum is derived by using specular reflection boundary conditions both in classical and quantum regimes. The frequency limit ω ≪ ωci ≪ ωce is considered and the dispersion relation for the Dust-Lower-Hybrid Surface Waves (DLHSW's) is derived for both classical and quantum plasma half-space and analyzed numerically. It is shown that the wave behavior changes as the quantum nature of the problem is considered.

Surface waves on the relativistic quantum plasma half-space

We present a theoretical investigation on the propagation of surface waves on the relativistic quantum plasma half-space. The dispersion relations of surface plasmon polaritons (SPPs) and electrostatic surface waves containing relativistic quantum corrected terms are derived. Results show that the frequency of SPPs has a blue-shift, and surface Langmuir oscillations can propagate on the cold plasma half-space due to quantum effects. Numerical evaluation indicates that quantum effects to SPPs and electrostatic surface waves are significant and observable.

Surface waves on a quantum plasma half-space

Surface modes are coupled electromagnetic/electrostatic excitations of free electrons near the vacuum-plasma interface and can be excited on a sufficiently dense plasma half-space. They propagate along the surface plane and decay in either sides of the boundary. In such dense plasma models, which are of interest in electronic signal transmission or in some astrophysical applications, the dynamics of the electrons is certainly affected by the quantum effects. Thus, the dispersion relation for the surface wave on a quantum electron plasma half-space is derived by employing the quantum hydrodynamical (QHD) and Maxwell–Poisson equations. The QHD include quantum forces involving the Fermi electron temperature and the quantum Bohm potential. It is found that, at room temperature, the quantum effects are mainly relevant for the electrostatic surface plasma waves in a dense gold metallic plasma.