Bloch oscillations of BEC in tilted optical lattices

Andrey Kolovsky

MPI fuer komplexer Systeme, 01187 Dresden, Germany and Kirensky Institute of Physics, 660036 Krasnoyarsk, Russia

We study the Bloch dynamics of Bose-Einstein condensate of cold atoms by using the formalism of the discrete nonlinear Schrödinger equation. Depending on the static force magnitude the system is shown to exhibit two qualitatively different regimes of Bloch oscillations - exponential decay for the static force magnitude less than some critical value (defined by the condensate density) and quasiperiodic oscillations in the opposite case. Relation of these regimes to the onset of chaos in the system is discussed.