We study proximity resonances and superradiance, scattering in waveguides, multiple scattering and decoherence in cold atom gases, multiple scattering including Rashba spin orbit coupling, guiding waves with walls of scatterers, boundary wall methods.

In one project, we investigated the possibility that linear arrays of atoms can guide matter waves, much as fiber optics guide light. Modeling the atomic line as a quasi-one-dimensional array of s-wave point scatterers embedded in two-dimensions,. we revealed how matter-wave guiding arises from the interplay of scattering phenomena with bands and conduction along the array. (Phys. Rev. A **76**, 013620, (2007))

Threshold resonance for a unit cell with five randomly placed scatterers (hard disks with *a*=0.1) depicted by the dots in the figure). For clarity, we plot only the scattered wave function; the incident wave is a plane wave and would be added to the scattered wave function to obtain the full wave function. (a) The quasibound state just below resonance, at wave number *k**d*=2*π*−0.3, becomes unbound (b) just above resonance, at *k**d*=2*π*+0.3.