Probing mean-field screening in a tilted incommensurate lattice

There has been recent interest in the competing roles of disorder and interactions on the dynamics of ultracold gases in optical lattices. Here, we investigate a weakly interacting Bose-Einstein condensate in a tilted incommensurate lattice potential. It is well known that both collisional interactions and disorder individually cause damping of Bloch oscillations. We explore the interplay between the two damping effects and observe a reduction in the disorder-induced damping rate due to the presence of interactions, consistent with screening of disorder.