论文标题
Yukawa流体的瞬时剪切模量
Instantaneous shear modulus of Yukawa fluids across coupling regimes
论文作者
论文摘要
从非常弱耦合的气态态到结晶点（Yukwa融化）的强耦合流体（Yukwa融化），对三维Yukawa系统的高频（瞬时）剪切模量进行了评估。这使我们能够通过增加耦合和颗粒间相关性来量化剪切刚性如何发展。从广泛的分子动力学（MD）模拟中获得了计算过量剪切模量所需的径向分布函数（RDF）。 MD结果表明，根据Roskilde-Simple Systems的同构理论，在与Yukawa固体熔体线平行的曲线上，流体RDF在平行于Yukawa固体的熔融线的曲线上出现。这种准通行性允许大量计算涉及RDF积分的数量（弹性模量仅代表一个相关的示例）。计算出的还原模量在弱耦合处随耦合参数线性生长，并在强耦合下接近准稳定渐近线。强耦合时的渐近值与现有的理论近似相当良好。
The high frequency (instantaneous) shear modulus of three-dimensional Yukawa systems is evaluated in a wide parameter range, from the very weakly coupled gaseous state to the strongly coupled fluid at the crystallization point (Yukwa melt). This allows us to quantify how shear rigidity develops with increasing coupling and inter-particle correlations. The radial distribution functions (RDFs) needed to calculate the excess shear modulus have been obtained from extensive molecular dynamics (MD) simulations. MD results demonstrate that fluid RDFs appear quasi-universal on the curves parallel to the melting line of a Yukawa solid, in accordance with the isomorph theory of Roskilde-simple systems. This quasi-universality, allows to simplify considerably calculations of quantities involving integrals of the RDF (elastic moduli represent just one relevant example). The calculated reduced shear modulus grows linearly with the coupling parameter at weak coupling and approaches a quasi-constant asymptote at strong coupling. The asymptotic value at strong coupling is in reasonably good agreement with the existing theoretical approximation.
