Dynamics of two colliding Bose-Einstein condensates in an elongated magnetostatic trap - art. no. 063607

We study the dynamics of two interacting Bose-Einstein condensates. by nume rically solving two coupled Gross-Pitaevskii equations at zero temperature. We consider the case of a sudden transfer of atoms between two trapped sta tes with different magnetic moments: the two condensates are initially crea ted with the same density profile, but are trapped into different magnetic potentials, whose minima are vertically displaced by a distance much larger than the initial size of both condensates. Then the two condensates begin to perform collective oscillations, undergoing a complex evolution, charact erized by collisions between the two condensates. We investigate the effect s of their mutual interaction on the center-of-mass oscillations and on the time evolution of the aspect ratios. Our theoretical analysis provides a u seful insight into the recent experimental observations by Maddaloni et al. [Phys. Rev. Lett. 85, 2413 (2000)].