We analyse the interaction of exciton and exciton-polariton condensates in semiconductor microcavity with a coherent acoustic wave. An analytical solution for the dispersion of excitations of coupled condensate-phonon system is found in the approximation of k-independent interactions. Accounting for k-dependence results in a stronger modification of the dispersion, and even in the appearance of the "roton instability" region.
@article{arxiv.1103.2003,
title = {Coherent interactions between phonons and exciton or exciton-polariton condensates},
author = {D. V. Vishnevsky and N. A. Gippius and I. A. Shelykh and D. D. Solnyshkov and G. Malpuech},
journal= {arXiv preprint arXiv:1103.2003},
year = {2015}
}