Description of longitudinal modes in moderately coupled Yukawa systems with the static local field correction

Longitudinal viscosity of 2D Yukawa liquids

The longitudinal viscosity $η_l$ is obtained for a two-dimensional (2D) liquid using a Green-Kubo method with a molecular dynamics simulation. The interparticle potential used has the Debye-Hückel or Yukawa form, which models a 2D dusty plasma. The longitudinal $η_l$ and shear $η_s$ viscosities are found to have values that match very closely, with only negligible differences for the entire range of temperatures that is considered. The bulk viscosity $η_b$ is determined to be either negligibly small or not a meaningful transport coefficient, for a 2D Yukawa liquid.

汤川流体的变分方法。II. 瞬时弹性模量和声速

Variational approach to Yukawa fluids. II. Instantaneous elastic moduli and sound velocities

研究利用基于玻戈留波夫不等式、以硬球流体为参考系统的变分方法评估汤川流体的弹性模量和声速，证明了该方法准确性，还评估绝热声速并分析了强弱耦合区域转变。

High-frequency elastic moduli of two-dimensional Yukawa fluids and solids

An approach to calculate high-frequency bulk and shear modului of two-dimensional (2D) weakly screened Yukawa fluids and solids is presented. Elastic moduli are directly related to sound velocities and other important characteristics of the system. In this article we discuss these relations and present exemplary calculation of the longitudinal, transverse, and instantaneous sound velocities and derive a differential equation for the Einstein frequency. Simple analytical results presented demonstrate good accuracy when compared with numerical calculations. The obtained results can be particular…

Unified description of sound velocities in strongly coupled Yukawa systems of different spatial dimensionality

Sound velocities in classical single-component fluids with Yukawa (screened Coulomb) interactions are systematically evaluated and analyzed in one-, two-, and three spatial dimensions (${\mathcal D}=1,2,3$). In the strongly coupled regime the convenient sound velocity scale is given by $\sqrt{Q^2/Δm}$, where $Q$ is the particle charge, $m$ is the particle mass, $n$ is the particle density, and $Δ=n^{-1/{\mathcal D}}$ is the unified interparticle distance. The sound velocity can be expressed as a product of this scaling factor and a dimension-dependent function of the screening parameter, $κ=Δ/…

Fluid approach to evaluate sound velocity in Yukawa systems (complex plasmas)

The conventional fluid description of multi-component plasma, supplemented by an appropriate equation of state for the macroparticle component, is used to evaluate the longitudinal sound velocity of Yukawa fluids. The obtained results are in very good agreement with those obtained earlier employing the quasi-localized charge approximation and molecular dynamics simulations in a rather broad parameter regime. Thus, a simple yet accurate tool to estimate the sound velocity across coupling regimes is proposed, which can be particularly helpful in estimating the dust-acoustic velocity in strongly …

Electric Field Induced Patterns and their Temperature Dependence in a Bent-Core Liquid Crystal

Two kinds of electroconvection (EC) patterns in an ether-bridged bent-core nematic liquid crystal material (BCN), which appear in different frequency ranges, are examined and compared in this paper. One is a longitudinal pattern with the stripes parallel to the orientation of the BCN and with a periodicity of approximately the cell thickness, occurring in the high frequency range of several hundreds Hz; the other one is oblique stripes, which results in a zig-zag pattern, and appears in the low frequency range of several tens Hz. In addition, within an intermediate frequency range, transformat…