Momentum transferred to a trapped Bose-Einstein condensate by stimulated light scattering - art. no. 063614

The response of a trapped Bose-Einstein condensed gas to a density perturba tion generated by a two-photon Bragg pulse is investigated by solving the t ime-dependent Gross-Pitaevskii equation. We calculate the total momentum im parted to the condensate as a function of both the time duration of the pul se and the frequency difference of the two laser beams. The role of the dyn amic response function in characterizing the time evolution of the system i s pointed out, with special emphasis to the phonon regime. Numerical simula tions are compared with the predictions of local-density approximation. The relevance of our results for the interpretation of current experiments is also discussed.