  We study the process of nonlinear stimulated Raman adiabatic passage within a
classical mean-fieldframework. Depending on the sign of interaction, the
breakdown of adiabaticity in the interactingnonintegrable system is not related
to bifurcations in the energy landscape, but rather to the emergence
ofquasistochastic motion that drains the followed quasistationary state.
Consequently, faster sweep rate,rather than quasistatic variation of
parameters, is better for adiabaticity
