Nonlinear interaction of compressional waves in a 2D dusty plasma crystal.
Nonlinear mixing and harmonic generation of compressional waves were studied in a 2D Yukawa (screened Coulomb) triangular lattice. The lattice was a monolayer of highly charged polymer microspheres levitated in a plasma sheath. Two sinusoidal waves with different frequencies were excited in the lattice by pushing the particles with modulated Ar+ laser beams. Waves at the sum and difference frequencies and harmonics were observed propagating in the lattice. Phonons interacted nonlinearly only above an excitation-power threshold due to frictional damping, as predicted by theory.
Nosenko
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V
Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA.
Avinash
K
K
Goree
J
J
Liu
B
B