Nonlinear atom-optical delta-kicked harmonic oscillator using a Bose-Einstein condensate

We experimentally investigate the atom-optical delta-kicked harmonic oscillator for the case of nonlinearity due to collisional interactions present in a Bose-Einstein condensate. A Bose condensate of rubidium atoms tightly confined in a static harmonic magnetic trap is exposed to a one-dimensional optical standing-wave potential that is pulsed on periodically. We focus on the quantum anti-resonance case for which the classical periodic behavior is simple and well understood. We show that after a small number of kicks the dynamics is dominated by dephasing of matter wave interference due to the finite width of the condensate's initial momentum distribution. In addition, we demonstrate that the nonlinear mean-field interaction in a typical harmonically confined Bose condensate is not sufficient to give rise to chaotic behavior.