Boundary-Dependent Chaotic Regions for a Bose--Einstein Condensate Interacting with Laser Field

Spatial chaos of a Bose--Einstein condensate perturbed by a weak laser
standing wave and a weak laser δ pulse is studied. By using the perturbed chaotic solution we investigate the new type of Melnikov chaotic regions, which depend on an integration constant c₀ determined by the boundary conditions. It is shown that when the |c₀| values are small, the chaotic region corresponds to small values of laser wave vector k, and the chaotic region for the larger k values is related to the large |c₀| values. The result is confirmed
numerically by finding the chaotic and regular orbits on the Poincaré section for the two different parameter regions. Thus, for a fixed c₀ the adjustment of k from a small value to large value can transform the chaotic region into the regular one or on the contrary, which suggests a feasible method for eliminating or generating Melnikov chaos.