To detect the looped Bloch bands of Bose-Einstein condensates in optical lattices

A loop structure was predicted to exist in the Bloch bands of Bose-Einstein condensates in optical lattices recently in [{\it Wu and Niu, Phys. Rev. A {\bf 61}, 023402 (2000)}]. We discuss how to detect experimentally the looped band with an accelerating optical lattice through extensive and realistic numerical simulations. We find that the loop can be detected through observing either nonlinear Landau-Zener tunneling or destruction of Bloch oscillations.