Bright solitons and self-trapping with a Bose-Einstein condensate of atoms in driventilted optical lattices

摘要

We discuss a method for creating bright matter solitons by loading a Bose-Einstein condensate of atoms in adriven tilted optical lattice. It is shown that one can realize the self-focusing regime for the wave-packet dynamicsby properly adjusting the phase of the driving field with respect to the phase of Bloch oscillations. If atom-atominteractions are larger than some critical value g_(min),this self-focusing regime is Followed by the formation ofbright solitons. Increasing the interactions above another critical value g_(max)makes this process unstable. Insteadof soliton formation one now meets the phenomenon of incoherent self-trapping. In this regime a fraction ofatoms is trapped in incoherent localized wave packets, while the remaining atoms spread ballistically.