Nonlinear Resonances in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>δ</mml:mi></mml:math>-Kicked Bose-Einstein Condensates

Abstract

We investigate the effect of atomic interactions on delta-kicked cold atoms. We show that the clearest signature of the nonlinear dynamics is a surprisingly abrupt cutoff that appears on the leading resonances. We show that this is due to an excitation path combining both Beliaev and Landau processes, with some analogies to nonlinear self-trapping. Investigation of dynamical instability reveals further symptoms of nonlinearity such as a regime of exponential oscillations.