We analyze the non-equilibrium quantum dynamics of a Bose-Einstein condensate that flows in an optical lattice on the basis of the Bose-Hubbard model. The time evolution of a condensate calculated by the dynamical Gutzwiller approximation has clarified that density modulations appear as a precursor phenomenon of the dynamical instability. Furthermore, the principal mode of modulations strongly depends on both the interparticle interaction strength and the rate of momentum acceleration. We show that these features of density modulations are well explained by the stability phase diagram obtained on the basis of the Bogoliubov theory.
ASJC Scopus subject areas
- Physics and Astronomy(all)