First direct measurement of optical phonons in 2D plasma crystals
arXiv:0907.5145 · doi:10.1103/PhysRevLett.103.215001
Abstract
Spectra of phonons with out-of-plane polarization were studied experimentally in a 2D plasma crystal. The dispersion relation was directly measured for the first time using a novel method of particle imaging. The out-of-plane mode was proven to have negative optical dispersion, comparison with theory showed good agreement. The effect of the plasma wakes on the dispersion relation is briefly discussed.
submitted to Physical Review Letters