arXiv:1911.09027 · Physical Review A
Bogoliubov excitations in the quasiperiodic kicked rotor: Stability of a kicked condensate and the quasi–insulator-to-metal transition
Benoît Vermersch, Dominique Delande, Jean Claude Garreau
Abstract
We study the dynamics of a Bose-Einstein condensate in the quasiperiodic kicked rotor described by a Gross-Pitaevskii equation confined in a toroidal trap. As the interactions are increased, Bogoliubov excitations appear and deplete the condensate; we characterize this instability by considering the population of the first Bogoliubov mode, and we show that it does not prevent, for small enough interaction strengths, the observation of the quasi--insulator-to-metal transition that replaces the Anderson transition of the noninteracting case. However, the predicted subdiffusion in momentum space is not observed in the stable region within experimentally accessible times. For higher interaction strengths, the condensate may be strongly depleted before this dynamical regimes set in.