Interaction of Rayleigh waves with 2D dipolar exciton gas: Impact of Bose-Einstein condensation

The theory of the interaction of a two-dimensional gas of indirect dipolar excitons with Rayleigh surface elastic waves has been developed. The absorption and renormalization of the phase velocity of a surface wave, as well as the drag of excitons by the surface acoustic wave and the generation of bulk acoustic waves by a two dimensional gas of dipolar excitons irradiated by external electromagnetic radiation, have been considered. These effects have been studied both in a normal phase at high temperatures and in a condensed phase of the exciton gas. The calculations have been performed in the ballistic and diffusion limits for both phases.