Röcker T B, Ivlev A V, Zhdanov S K, Morfill G E
Max Planck Institute for Extraterrestrial Physics, 85741 Garching, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jan;89(1):013104. doi: 10.1103/PhysRevE.89.013104. Epub 2014 Jan 15.
We study the effects of the particle-wake interactions on the dispersion and polarization of dust lattice wave modes in two-dimensional plasma crystals. Most notably, the wake-induced coupling between the modes causes the branches to "attract" each other, and their polarizations become elliptical. Upon the mode hybridization the major axes of the ellipses (remaining mutually orthogonal) rotate by 45°. To demonstrate the importance of the obtained results for experiments, we plot representative particle trajectories and spectral densities of the longitudinal and transverse waves. These characteristics reveal distinct fingerprints of the mixed polarization. Furthermore, we show that at strong coupling the hybrid mode is significantly shifted towards smaller wave numbers, away from the border of the first Brillouin zone (where the hybrid mode is localized for a weak coupling).
我们研究了二维等离子体晶体中粒子-尾流相互作用对尘埃晶格波模式色散和极化的影响。最显著的是，模式之间的尾流诱导耦合导致分支相互“吸引”，并且它们的极化变为椭圆形。在模式杂化时，椭圆的长轴（保持相互正交）旋转45°。为了证明所得结果对实验的重要性，我们绘制了纵向和横向波的代表性粒子轨迹和谱密度。这些特征揭示了混合极化的独特特征。此外，我们表明，在强耦合时，混合模式显著向较小波数移动，远离第一布里渊区的边界（在弱耦合时混合模式局域在此处）。
