Macroscopic quantum tunneling and resonances in coupled Bose-Einstein condensates with oscillating atomic scattering length

摘要

We study the macroscopic quantum tunneling, self-trapping phenomena in twoweakly coupled Bose-Einstein condensates with periodically time-varying atomicscattering length. The resonances in the oscillations of the atomic populations areinvestigated. We consider oscillations in the cases of macroscopic quantumtunneling and the self-trapping regimes. The existence of chaotic oscillationsin the relative atomic population due to overlaps between nonlinear resonancesis showed. We derive the whisker-type map for the problem and obtain theestimate for the critical amplitude of modulations leading to chaos. Thediffusion coefficient for motion in the stochastic layer near separatrix iscalculated. The analysis of the oscillations in the rapidly varying case showsthe possibilty of stabilization of the unstable Pi-mode regime.