Experiments with two colliding Bose-Einstein condensates in an elongated magneto-static trap

We review some experiments performed with two Rb-87 Bose-Einstein condensates in an elongated magneto-static trap. The two condensates, being in different internal Zeeman state (\F = 2, m(f) = 2> and \F = 2, m(f) = 1>), experience external parabolic potentials that differ by both curvature and equilibrium position. The dynamics of the system is characterized by periodic collisions between the two condensates, which strongly affect their center-of-mass and shape oscillations. In particular, we show that both an amplitude damping and a frequency shift occur in the large center-of-mass oscillations of the \F = 2, m(f) = 1> condensate. The experimental data are quantitatively analyzed and found in agreement with the Gross-Pitaevskii theory for two interacting condensates at zero temperature.