Mode coupling for phonons in a single-layer dusty plasma crystal.
New modes in a dusty plasma result from coupling of differently polarized phonons. A single horizontal layer of charged microparticles, confined so that vertical as well as horizontal motions are possible, usually exhibits three modes. An experiment shows that mode coupling leads to a new hybrid mode and another new mode. Coupling also leads to a recently reported hybrid mode and nondispersive mode, shown here to occur in an unmelted lattice. A linear theory based on ion wakes is able to predict some, but not all, of these modes. Other multiphase systems could exhibit similar mode coupling.
Liu
Bin
B
Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA.
Goree
J
J
Feng
Yan
Y