Signatures of quantum stability in a classically chaotic system
  We experimentally and numerically investigate the quantum accelerator mode dynamics of an atom optical realization of the quantum delta-kicked accelerator, whose classical dynamics are chaotic. Using a Ramsey-type experiment, we observe interference, demonstrating that quantum accelerator modes are formed coherently. We construct a link between the behavior of the evolution's fidelity and the phase space structure of a recently proposed pseudoclassical map, and thus account for the observed interference visibilities. 
S. Schlunk, M.B. d'Arcy, S.A. Gardiner, D. Cassettari, R.M. Godun, and   G.S. Summy