Damping of Bloch oscillations in the Hubbard model
  Using nonequilibrium dynamical mean-field theory, we study the isolated Hubbard model in a static electric field in the limit of weak interactions. Linear response behavior is established at long times, but only if the interaction exceeds a critical value, below which the system exhibits an AC-type response with Bloch oscillations. The transition from AC to DC response is defined in terms of the universal long-time behavior of the system, which does not depend on the initial condition. 
Martin Eckstein and Philipp Werner
cond-mat.str-el