Research Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences, H-1525 Budapest, P.O. Box 49, Hungary.
Phys Rev Lett. 2009 Dec 11;103(24):245002. doi: 10.1103/PhysRevLett.103.245002. Epub 2009 Dec 9.
A classical dusty plasma experiment was performed using two different dust grain sizes to form a strongly coupled asymmetric bilayer (two closely spaced interacting monolayers) of two species of charged dust particles. The observation and analysis of the thermally excited particle oscillations revealed the collective mode structure and dispersion (wave propagation) in this system; in particular, the existence of the theoretically predicted k=0 energy (frequency) gap was verified. Equilibrium molecular-dynamics simulations were performed to emulate the experiment, assuming Yukawa-type interparticle interaction. The simulations and analytic calculations based both on lattice summation and on the quasilocalized charge approximation approach are in good agreement with the experimental findings and help in identifying and characterizing the observed phenomena.
采用两种不同粒径的尘埃颗粒进行了经典的尘埃等离子体实验，以形成两种带电尘埃颗粒的强耦合不对称双层（两个紧密间隔的相互作用的单层）。对热激发颗粒振荡的观察和分析揭示了该体系中的集体模式结构和色散（波传播）；特别是，验证了理论预测的 k=0 能量（频率）间隙的存在。进行了平衡分子动力学模拟，以模拟实验，假设采用 Yukawa 型颗粒间相互作用。基于晶格求和和准局域电荷近似方法的模拟和解析计算与实验结果吻合良好，有助于识别和描述观察到的现象。
