Waves in dusty plasma crystals with dipole interactions

Nonsymmetrical effective interactions between dust grains in dusty plasmas can arise from a variety of mechanisms such as nonuniform charging, ion focusing and wakes, and induced grain polarization. These effects can be included by describing the total effective interaction in terms of its first two multipoles: the monopole term which corresponds to the usual screened Coulomb interaction, and the dipole term which can be either attractive or repulsive depending on the relative orientation between grains. We consider dust waves propagating along the dipole axis in such a system (in its crystalline phase) and dispersion relations are presented.