Excitation of surface dust-acoustic waves and surface wake Potentials in a complex plasma

A dielectric response theory of a complex plasma is developed taking into account the discontinuity at the surfaces of a Coulomb crystal. For simplicity, at first the cold plasma approximation is employed to show how a surface wake potential and a "ripple'' potential are formed by a fast charged particle moving parallel and perpendicular to the surface, respectively. Second, the dispersion relation of surface dust-acoustic waves (SDAW) is derived from the dielectric response function. It is found that the dispersion of SDAW depends on the local coordinate perpendicular to the surface. The formation of surface wake and ripple potentials due to SDAW excitation are also demonstrated.