Semiclassical Dynamics and Time Correlations in Two‐Component Plasmas

A dynamic longitudinal internal conductivity model, derived from the classical method of moments, is applied to the analysis of recent simulation data and reflectivity measurements of shock-compressed dense xenon plasmas. This model satisfies both the non-zero f −sum rule and the second non-zero sum rule, and reproduces the non-monotonicity of the conductivity of dense plasmas beyond the domain of applicability of the Drude-Lorentz model. The Drude-Lorentz model from the point of view of the theory of momentsThe classical model for the (internal) conductivity of dense plasmas and metals,is characterized by two static parameters, the static conductivity σ 0 = σ (ω = 0) = n e e 2 τm −1 = (4π) −1 ω 2 p τ and the relaxation time τ . Here n e is the number density of electrons in the system, −e and m are the electronic charge and mass, and ω p is the plasma frequency.In addition to direct measurements, the static conductivity value can be obtained as [1]Here σ ext (ω) is the external dynamic conductivity of the Coulomb system related to the internal conductivity through the well-known formula 1 [2]:Mathematically, the DL function, σ DL (z), is a simple Nevanlinna (response) function 2 with a single simple pole in the lower half-plane. In addition, the real part of σ DL (z) possesses a single finite frequency moment, which is known also as the f -sum rule:

Section: The Drude-lorentz Model From the Point Of View Of The Theorymentioning

confidence: 98%

Two‐moment modelling of the dynamic longitudinal conductivity of strongly coupled Coulomb systems

Ballester

Ткаченко

2005

“…Due to the quantum effects (Heisenberg-and Pauli-effects), the electron-electron interaction is rather weak [30] and may be neglected in many cases. The electron-ion interaction is described by an appropriate pseudo-potential V (r jk ) with finite value at small distance [31] including also screening:…”

Section: Interactions and Electron-ion Dynamicsmentioning

confidence: 99%

“…The quantum effects are expressed by one constant α which is in a first-order approximation given by [30] …”

Section: Interactions and Electron-ion Dynamicsmentioning

confidence: 99%

“…Take the N electrons located at the positions y j moving in the nonuniform, and, in general, time-dependent electric field generated by the positive ions located at x k and by the other electrons. The effective interaction between two electrons at y i and y j (distance: r ij = |y i − y j |) is modelled by the quantum-statistical (screened) pseudo-potential of Kelbg-Deutsch type [30] …”

Section: Interactions and Electron-ion Dynamicsmentioning

confidence: 99%

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Nonlinear Ionic Excitations, Dynamic Bound States, and Nonlinear Currents in a One‐dimensional Plasma

Chetverikov

Ébeling

Velarde

2005

Self Cite

We study the role of nonlinear effects in a classical one-dimensional model of a conducting electron-ion system. In particular we investigate the excitations of strongly nonlinear deformed phonons (cnoidal waves, solitons) on electric currents. We show that in a nonlinear lattice a new type of dynamic bound states of solitons and electrons ("solectrons") may be formed. In our simulations we use Langevin dynamics with N = 10 ions and periodic boundary conditions. The electron-ion interaction is modelled by screened Coulomb forces with appropriate cut-off at small distance; the ion-ion interaction is approximated by an exponential repulsion. Under the influence of a weak external electrical field, the charged particles and "solectrons" yield a stochastic current in the direction of the field. We study several mechanisms to generate and maintain the "solectrons". Then we show how the system develops driven ionic solitons moving opposite to the field. Since the extra current driven by the solitons is (nearly) independent on the external field we find a strongly nonlinear current field characteristics corresponding for small fields to a highly conducting state.

“…The pairwise electron-ion and ion-ion interacions are set to the corresponding unscreened HGK potentials. The electron-electron interaction potential, not provided by the unscreened HGK model, is chosen to be of the corrected Kelbg type [60]. Random single-particle displacements with adjustable amplitude are used to keep the www.cpp-journal.org Metropolis algorithm acceptance ratio around 0.5.…”

Section: Electric Microfield Distributions At the Location Of An Ion mentioning

confidence: 99%

Electric Microfield Distributions in Alkali Plasmas with Account of the Ion Structure

Sadykova¹,

Ébeling

Valuev

et al. 2009

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The e − e , e − i, i − i and charge-charge static structure factors are calculated for alkali and Be 2+ plasmas using the method described by Gregori et al. in [1]. The dynamic structure factors for alkali plasmas are calculated using the method of moments [2], [3]. In both methods the screened Hellmann-Gurskii-Krasko potential, obtained on the basis of Bogolyubov's method, has been used taking into account not only the quantum-mechanical effects but also the ion structure [4]. PACS. 52.27.Aj Alkali and alkaline earth plasmas, Static and dynamic structure factors-52.25.Kn Ther-modynamics of plasmas-52.38.Ph X-ray scattering