The implementation of stochastic cooling in a confined geometry is discussed, where the boundary shape is found to be an independent control parameter for arriving at a variety of final spatial and momentum distributions. Results for integrable and nonintegrable geometries are contrasted in terms of...

We study quantum dynamical tunneling between two symmetry-related islands of stability in the phase space of a classically chaotic system. The setting for these experiments is the motion of carefully prepared samples of cesium atoms in an amplitude-modulated standing wave of light. We examine the dependence...

We demonstrate real-time feedback control of atomic center of mass motion in a cloud of laser cooled cesium atoms. Using the velocity measurementt echnique of recoil-inducedr esonances,t he average velocity of the atomic cloud is obtained. This information is used to give a correction from a moving optical...

We report an experimental study of the spatial distribution of ultracold cesium atoms exposed to a series of kicks from a standing wave of light.We observe cumulative focusing, leading to a spatial array of atoms which is of interest for atomic lithography. To observe the spatial distribution, we developed...

We report the direct observation of quantum dynamical tunneling of atoms between separated momentum regions in phase space. We study how the tunneling oscillations are affected as a quantum symmetry is broken and as the initial atomic state is changed. We also provide evidence that the tunneling rate is...

The generation of internal gravity waves by tidal flow over topography is an important oceanic process that redistributes tidal energy in the ocean. Internal waves reflect from boundaries, creating harmonics and mixing. We use laboratory experiments and two-dimensional numerical simulations of the Navier’Stokes...

We study the localization properties of a one-dimensional incommensurate potential in the full quantum regime. In the system under consideration, and for amplitudes of the potential that are not too weak, the spectrum contains both localized and extended states, with one or more mobility edges. We show...

One of the central paradigms for classical and quantum chaos in conservative systems is the twodimensional billiard in which particles are confined to a closed region in the plane, undergoing elastic collisions with the walls and free motion in between. We report the first realization of billiards using ultracold...

Atomic motion in a time-dependent standing wave of light provides an almost ideal experimental system for the study of quantum chaos, due to the nonlinearity of the potential combined with negligible dissipation. In our first experiments with sodium atoms we observed dynamical localization, a quantum...