Nosenko V, Goree J, Skiff F
Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Jan;73(1 Pt 2):016401. doi: 10.1103/PhysRevE.73.016401. Epub 2006 Jan 3.
Bispectral analysis was used to study the nonlinear interaction of compressional waves in a two-dimensional strongly coupled dusty plasma. A monolayer of highly charged polymer microspheres was suspended in a plasma sheath. The microspheres interacted with a Yukawa potential and formed a triangular lattice. Two sinusoidal pump waves with different frequencies were excited in the lattice by pushing the particles with modulated Ar+ laser beams. Coherent nonlinear interaction of the pump waves was shown to be the mechanism of generating waves at the sum, difference, and other combination frequencies. However, coherent nonlinear interaction was ruled out for certain combination frequencies, in particular, for the difference frequency below an excitation-power threshold, as predicted by theory.
双谱分析被用于研究二维强耦合尘埃等离子体中压缩波的非线性相互作用。单层高电荷聚合物微球悬浮在等离子体鞘层中。微球通过 Yukawa 势相互作用并形成三角晶格。通过用调制的 Ar+激光束推动粒子，在晶格中激发了两个不同频率的正弦泵浦波。泵浦波的相干非线性相互作用被证明是在和频、差频及其他组合频率处产生波的机制。然而，正如理论所预测的，对于某些组合频率，特别是低于激发功率阈值的差频，相干非线性相互作用被排除。
