Condensation of phonons in an ultracold Bose gas
arXiv:cond-mat/0609159 · doi:10.1016/j.physleta.2006.09.106
Abstract
We consider the generation of longitudinal phonons in an elongated Bose-condensed gas at zero temperature due to parametric resonance as a result of the modulation of the transverse trap frequency. The nonlinear temporal evolution with account of the phonon-phonon interaction leads self-consistently to the formation of the stationary state with the macroscopic occupation of a single phonon quantum state.
5 pages, 1 figure, submitted to Phys.Rev.Letters