Ion acoustic waves in ultracold neutral plasmas.
We photoionize laser-cooled atoms with a laser beam possessing spatially periodic intensity modulations to create ultracold neutral plasmas with controlled density perturbations. Laser-induced fluorescence imaging reveals that the density perturbations oscillate in space and time, and the dispersion relation of the oscillations matches that of ion acoustic waves, which are long-wavelength, electrostatic, density waves.
Castro
J
J
Department of Physics and Astronomy and Rice Quantum Institute, Rice University, Houston, Texas 77005, USA.
McQuillen
P
P
Killian
T C
TC