Simulation of expanding BECs and matter-wave lensing

Kurzfassung

The extended micro-gravity conditions afforded by cold-atom experiments in space enable free-evolution times of many seconds, which can be exploited in high-precision measurements based on atom interferometry. However, in order to reach such long evolution times, it is necessary to employ ultracold atoms combined with matter-wave lensing techniques, and a detailed modeling is required. Here we present the results of 3D numerical simulations of BECs freely expanding for tens of seconds. As an application, we investigate the long-time behaviour of a BEC whose expansion has been collimated through matter-wave lensing. In particular, we examine the role played by the repulsive mean-field interaction and by quantum effects due to Heisenberg's uncertainty principle and the finite size of the BEC.