Dynamics of Bose-Einstein condensate in driven tilted optical lattices

We study the dynamics of Bose-Einstein condensate in one-dimensional driven tilted periodic optical lattices by using variational approximation and numerical simulation, Rich phenomena are revealed, including diffusion, self-trapping, breather and soliton, which strongly depend on the atomic interaction, the amplitude of the modulation, the constant force and the phase difference between the Bloch oscillations and the drive. The critical conditions for the dynamical transition from diffusion to self-trapping and for the formation of the soliton are derived analytically. In addition, the phase diagrams of dynamical transitions are presented in full parameters space. We find that the dynamics of the system can be completely controlled by adjusting the constant force, the amplitude of the modulation and the phase difference between the Bloch oscillations and the drive. The results are confirmed by the direct numerical simulation of the full Gross-Pitaevskii equation. (C) 2018 Elsevier B.V. All rights reserved.