The influence of the interaction between quasiparticles on parametric resonance in Bose–Einstein condensates

We analyse a uniform weakly interacting bosonic gas undergoing a periodic oscillation of the interaction constant. This, within the Bogoliubov approximation, leads to the creation of atomic pairs with well defined opposite velocities. We show how the interaction between quasiparticles, omitted in the Bogoliubov approximation, significantly changes the atom pair creation process and the properties of the scattered atoms. (paper)